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Search: a089545 -id:a089545
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a(n)=(A089545(n)+1)/2.
+20
1
3, 7, 9, 13, 19, 15, 21, 31, 27, 33, 33, 43, 43, 37, 45, 51, 57, 49, 55, 63, 73, 73, 75, 91, 69, 87, 79, 93, 99, 111, 97, 103, 93, 85, 115, 129, 133, 117, 103, 135, 121, 133, 111, 147, 139, 157, 163, 159, 153, 141, 145, 183, 183, 201, 169, 189, 175, 153, 189, 211
OFFSET
1,1
LINKS
KEYWORD
nonn
AUTHOR
Ray Chandler, Nov 16 2003
STATUS
approved
Sum of legs of primitive Pythagorean triangles having legs that add up to a square, sorted on hypotenuse.
+10
18
49, 289, 529, 961, 2209, 1681, 2401, 5041, 5329, 6241, 7921, 9409, 12769, 10609, 14161, 14161, 16129, 18769, 22801, 25921, 25921, 27889, 36481, 39601, 37249, 47089, 47089, 54289, 49729, 58081, 69169, 73441, 66049, 57121, 78961, 82369
OFFSET
1,1
LINKS
MATHEMATICA
terms = 1000; jmax = 100; kmax = 200;
Reap[Do[If[CoprimeQ[j, k], e = j^2 - j k + k^2/2; f = j k; If[e > f, Sow[{e^2 + f^2, (j^2 - k^2/2)^2}]]], {j, 1, jmax}, {k, 2, kmax, 2}]][[2, 1]] // Sort // #[[;; terms, 2]]& (* Jean-François Alcover, Mar 05 2020 *)
KEYWORD
nonn
AUTHOR
Ray Chandler, Nov 16 2003
STATUS
approved
Ordered hypotenuses of primitive Pythagorean triangles having legs that add up to a square.
+10
17
41, 205, 389, 689, 1565, 1625, 1781, 3865, 4105, 4549, 5989, 7421, 9161, 9685, 10225, 10685, 13025, 17509, 17965, 18329, 21349, 21701, 25801, 33161, 33169, 33529, 36749, 38581, 39709, 49325, 51649, 52429, 52721, 56785, 57065, 67205, 70801
OFFSET
1,1
REFERENCES
F. Rubin, "Squared" Pythagorean Triples, Solution to problem 2306, J. Recreational Mathematics, Vol. 29, No. 1, 1998, p. 73.
LINKS
FORMULA
a(n)=e^2+f^2, where e>f, e=j^2 - jk + k^2/2 and f=jk for coprime pairs (j, k) with k even.
EXAMPLE
9161 is in the sequence because of the triple 5289^2 + 7480^2 = 9161^2 where we have 5289+7480=113^2.
Similarly, 205 belongs to the triple (133,156,205) and 133+156=17^2.
MATHEMATICA
terms = 1000; jmax = 100; kmax = 200;
Reap[Do[If[CoprimeQ[j, k], e = j^2 - j k + k^2/2; f = j k; If[e > f, Sow[e^2 + f^2]]], {j, 1, jmax}, {k, 2, kmax, 2}]][[2, 1]] // Union // Take[#, terms]& (* Jean-François Alcover, Mar 04 2020 *)
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Nov 06 2003
STATUS
approved
Values j of pairs (j,k) that generate A088319(n).
+10
17
1, 1, 5, 1, 7, 7, 1, 1, 9, 9, 3, 1, 11, 11, 3, 11, 1, 5, 13, 13, 1, 13, 3, 1, 15, 15, 5, 3, 15, 1, 5, 17, 17, 7, 17, 17, 1, 5, 7, 3, 19, 19, 19, 19, 5, 1, 19, 3, 21, 21, 7, 1, 21, 21, 7, 5, 23, 9, 23, 1, 23, 23, 3, 23, 7, 5, 9, 1, 23, 3, 25, 25, 7, 25, 25, 5, 25, 1, 7, 9, 27, 25, 27, 27, 5, 11, 1
OFFSET
1,3
LINKS
MATHEMATICA
terms = 1000; jmax = 100; kmax = 200;
Reap[Do[If[CoprimeQ[j, k], e = j^2 - j k + k^2/2; f = j k; If[e > f, Sow[{e^2 + f^2, j, k}]]], {j, 1, jmax}, {k, 2, kmax, 2}]][[2, 1]] // Sort // #[[;; terms, 2]]& (* Jean-François Alcover, Mar 05 2020 *)
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Nov 14 2003
EXTENSIONS
Corrected and extended by Ray Chandler, Nov 16 2003
STATUS
approved
Values k of pairs (j,k) that generate A088319(n).
+10
17
4, 6, 2, 8, 2, 4, 10, 12, 4, 2, 14, 14, 4, 6, 16, 2, 16, 18, 6, 4, 18, 2, 20, 20, 8, 4, 22, 22, 2, 22, 24, 6, 8, 24, 4, 2, 24, 26, 26, 26, 8, 6, 10, 4, 28, 26, 2, 28, 8, 10, 30, 28, 4, 2, 32, 32, 10, 32, 8, 30, 12, 6, 32, 4, 34, 34, 34, 32, 2, 34, 12, 8, 36, 14, 6, 36, 4, 34, 38, 38, 10, 2
OFFSET
1,1
LINKS
MATHEMATICA
terms = 1000; jmax = 100; kmax = 200;
Reap[Do[If[CoprimeQ[j, k], e = j^2 - j k + k^2/2; f = j k; If[e > f, Sow[{e^2 + f^2, j, k}]]], {j, 1, jmax}, {k, 2, kmax, 2}]][[2, 1]] // Sort // #[[;; terms, 3]]& (* Jean-François Alcover, Mar 05 2020 *)
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Nov 14 2003
EXTENSIONS
Corrected and extended by Ray Chandler, Nov 16 2003
STATUS
approved
Square root of sum of legs of primitive Pythagorean triangles having legs that add up to a square, sorted on hypotenuse.
+10
17
7, 17, 23, 31, 47, 41, 49, 71, 73, 79, 89, 97, 113, 103, 119, 119, 127, 137, 151, 161, 161, 167, 191, 199, 193, 217, 217, 233, 223, 241, 263, 271, 257, 239, 281, 287, 287, 313, 289, 329, 329, 343, 311, 353, 367, 337, 359, 383, 409, 391, 401, 391, 433, 439, 463
OFFSET
1,1
COMMENTS
Numbers whose square is the sum of the legs of primitive Pythagorean triangles with hypotenuse A088319(n).
LINKS
FORMULA
a(n) = abs(j^2 - k^2/2), where j=A088515(n), k=A088516(n).
a(n) = sqrt(A089552(n)).
EXAMPLE
31 is in the sequence because it is associated with the primitive Pythagorean triangle (400,561,689) where 400+561=31^2.
MATHEMATICA
terms = 1000; jmax = 100; kmax = 200;
Reap[Do[If[CoprimeQ[j, k], e = j^2 - j k + k^2/2; f = j k; If[e > f, Sow[{e^2 + f^2, Abs[j^2 - k^2/2]}]]], {j, 1, jmax}, {k, 2, kmax, 2}]][[2, 1]] // Sort // #[[;; terms, 2]]& (* Jean-François Alcover, Mar 05 2020 *)
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Nov 17 2003
EXTENSIONS
More terms from Ray Chandler, Nov 16 2003
STATUS
approved
a(n)=(A088515(n)+1)/2.
+10
17
1, 1, 3, 1, 4, 4, 1, 1, 5, 5, 2, 1, 6, 6, 2, 6, 1, 3, 7, 7, 1, 7, 2, 1, 8, 8, 3, 2, 8, 1, 3, 9, 9, 4, 9, 9, 1, 3, 4, 2, 10, 10, 10, 10, 3, 1, 10, 2, 11, 11, 4, 1, 11, 11, 4, 3, 12, 5, 12, 1, 12, 12, 2, 12, 4, 3, 5, 1, 12, 2, 13, 13, 4, 13, 13, 3, 13, 1, 4, 5, 14, 13, 14, 14, 3, 6, 1, 2, 5, 4, 14, 6
OFFSET
1,3
LINKS
KEYWORD
nonn
AUTHOR
Ray Chandler, Nov 16 2003
STATUS
approved
a(n)=A089551(n)/2.
+10
17
2, 21, 35, 68, 161, 14, 155, 294, 306, 423, 483, 497, 902, 231, 984, 869, 776, 315, 1209, 1898, 1143, 1547, 2670, 1610, 1020, 3390, 2585, 3927, 2505, 2189, 4380, 5253, 3332, 84, 5474, 3791, 2892, 6695, 2093, 7449, 6764, 8607, 2945, 8246, 9590, 3731, 5453
OFFSET
1,1
LINKS
KEYWORD
nonn
AUTHOR
Ray Chandler, Nov 16 2003
STATUS
approved
Values f of pairs (e,f) that generate A088319(n).
+10
3
4, 6, 10, 8, 14, 28, 10, 12, 36, 18, 42, 14, 44, 66, 48, 22, 16, 90, 78, 52, 18, 26, 60, 20, 120, 60, 110, 66, 30, 22, 120, 102, 136, 168, 68, 34, 24, 130, 182, 78, 152, 114, 190, 76, 140, 26, 38, 84, 168, 210, 210, 28, 84, 42, 224, 160, 230, 288, 184, 30, 276, 138, 96, 92
OFFSET
1,1
LINKS
KEYWORD
nonn
AUTHOR
Ray Chandler, Nov 16 2003
STATUS
approved
Radius of inscribed circle within primitive Pythagorean triangles having legs that add up to a square, sorted on hypotenuse.
+10
3
4, 42, 70, 136, 322, 28, 310, 588, 612, 846, 966, 994, 1804, 462, 1968, 1738, 1552, 630, 2418, 3796, 2286, 3094, 5340, 3220, 2040, 6780, 5170, 7854, 5010, 4378, 8760, 10506, 6664, 168, 10948, 7582, 5784, 13390, 4186, 14898, 13528, 17214, 5890, 16492, 19180
OFFSET
1,1
LINKS
KEYWORD
nonn
AUTHOR
Ray Chandler, Nov 16 2003
STATUS
approved

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