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Search: a192170 -id:a192170
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Monotonic ordering of nonnegative differences 2^i - 3^j, for 40 >= i >= 0, j >= 0.
+10
9
0, 1, 3, 5, 7, 13, 15, 23, 29, 31, 37, 47, 55, 61, 63, 101, 119, 125, 127, 175, 229, 247, 253, 255, 269, 295, 431, 485, 503, 509, 511, 781, 943, 997, 1015, 1021, 1023, 1319, 1631, 1805, 1909, 1967, 2021, 2039, 2045, 2047, 3367, 3853, 4015, 4069, 4087, 4093
OFFSET
1,3
COMMENTS
Comments from N. J. A. Sloane, Oct 21 2019: (Start)
Warning: Note the definition assumes i <= 40.
Because of this assumption, it is not true that this is (except for a(1)=0) the complement of A075824 in the odd integers.
However, by definition, it is the complement of A328077.
(End)
All 52 sequences in this set are finite. - Georg Fischer, Nov 16 2021
LINKS
Rok Cestnik, Table of n, a(n) for n = 1..534 [truncated to 2^40-1 by Georg Fischer, Nov 16 2021]
H. Gauchman and I. Rosenholtz (Proposers), R. Martin (Solver), Difference of prime powers, Problem 1404, Math. Mag., 65 (No. 4, 1992), 265; Solution, Math. Mag., 66 (No. 4, 1993), 269.
Math Overflow, 3^n - 2^m = +-41 is not possible. How to prove it?, Several contributors, Jun 29 2010.
EXAMPLE
The differences accrue like this:
1-1
2-1
4-3.....4-1
8-3.....8-1
16-9....16-3....16-1
32-27...32-9....32-3....32-1
64-27...64-9....64-3....64-1
MATHEMATICA
c = 2; d = 3; t[i_, j_] := c^i - d^j;
u = Table[t[i, j], {i, 0, 40}, {j, 0, i*Log[d, c]}];
v = Union[Flatten[u ]]
CROSSREFS
Cf. A075824, A173671, A192111, A328077 (complement).
For primes, see A007643, A007644, A321671.
This is the first of a set of 52 similar sequences:
A192110: 2^i-3^j, A192111: 3^i-2^j, A192112: 2^i-4^j, A192113: 4^i-2^j, A192114: 2^i-5^j, A192115: 5^i-2^j, A192116: 2^i-6^j, A192117: 6^i-2^j,
A192118: 2^i-7^j, A192119: 7^i-2^j, A192120: 2^i-8^j, A192121: 8^i-2^j, A192122: 2^i-9^j, A192123: 9^i-2^j, A192124: 2^i-10^j, A192125: 10^i-2^j,
A192147: 3^i-4^j, A192148: 4^i-3^j, A192149: 3^i-5^j, A192150: 5^i-3^j, A192151: 3^i-6^j, A192152: 6^i-3^j, A192153: 3^i-7^j, A192154: 7^i-3^j,
A192155: 3^i-8^j, A192156: 8^i-3^j, A192157: 3^i-9^j, A192158: 9^i-3^j, A192159: 3^i-10^j, A192160: 10^i-3^j, A192161: 4^i-5^j, A192162: 5^i-4^j,
A192163: 4^i-6^j, A192164: 6^i-4^j, A192165: 4^i-7^j, A192166: 7^i-4^j, A192167: 4^i-8^j, A192168: 8^i-4^j, A192169: 4^i-9^j, A192170: 9^i-4^j,
A192171: 4^i-10^j, A192172: 10^i-4^j, A192193: 5^i-6^j, A192194: 6^i-5^j, A192195: 5^i-7^j, A192196: 7^i-5^j, A192197: 5^i-8^j, A192198: 8^i-5^j,
A192199: 5^i-9^j, A192200: 9^i-5^j, A192201: 5^i-10^j, A192202: 10^i-5^j.
KEYWORD
nonn,fini
AUTHOR
Clark Kimberling, Jun 23 2011
STATUS
approved
Monotonic ordering of nonnegative differences 2^i-4^j, for 40>=i>=0, j>=0.
+10
3
0, 1, 3, 4, 7, 12, 15, 16, 28, 31, 48, 60, 63, 64, 112, 124, 127, 192, 240, 252, 255, 256, 448, 496, 508, 511, 768, 960, 1008, 1020, 1023, 1024, 1792, 1984, 2032, 2044, 2047, 3072, 3840, 4032, 4080, 4092, 4095, 4096, 7168, 7936, 8128, 8176, 8188, 8191, 12288
OFFSET
1,3
MATHEMATICA
c = 2; d = 4; t[i_, j_] := c^i - d^j;
u = Table[t[i, j], {i, 0, 40}, {j, 0, i*Log[d, c]}];
v = Union[Flatten[u ]]
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jun 23 2011
STATUS
approved
Monotonic ordering of nonnegative differences 4^i-9^j, for 40>= i>=0, j>=0.
+10
3
0, 3, 7, 15, 55, 63, 175, 247, 255, 295, 943, 1015, 1023, 3367, 4015, 4087, 4095, 6487, 9823, 15655, 16303, 16375, 16383, 58975, 64807, 65455, 65527, 65535, 203095, 255583, 261415, 262063, 262135, 262143, 517135, 989527, 1042015, 1047847, 1048495, 1048567
OFFSET
1,2
MATHEMATICA
c = 4; d = 9; t[i_, j_] := c^i - d^j;
u = Table[t[i, j], {i, 0, 40}, {j, 0, i*Log[d, c]}];
v = Union[Flatten[u ]]
CROSSREFS
Cf. A192170.
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jun 24 2011
STATUS
approved

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