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A160805
a(n) = (2*n^3 + 9*n^2 + n + 24) / 6.
3
4, 6, 13, 27, 50, 84, 131, 193, 272, 370, 489, 631, 798, 992, 1215, 1469, 1756, 2078, 2437, 2835, 3274, 3756, 4283, 4857, 5480, 6154, 6881, 7663, 8502, 9400, 10359, 11381, 12468, 13622, 14845, 16139, 17506, 18948, 20467, 22065, 23744, 25506, 27353, 29287
OFFSET
0,1
COMMENTS
Arithmetic progression of third order; a(n+1)-a(n) = A008865(n+2);
a(n) = A101986(n) + 4.
REFERENCES
R. Courant, Differential and Integral Calculus Vol. I (Blackie&Son, 1937), ch. I.4, Example 5, p.29.
FORMULA
a(n) = (2*n^3 + 9*n^2 + n + 24) / 6.
From Wesley Ivan Hurt, Aug 29 2015: (Start)
G.f.: (4-10*x+13*x^2-5*x^3)/(x-1)^4.
a(n) = 4*a(n-1)-6*a(n-2)+4*a(n-3)-a(n-4), n>3. (End)
MAPLE
A160805:=n->(2*n^3+9*n^2+n+24)/6: seq(A160805(n), n=0..80); # Wesley Ivan Hurt, Aug 29 2015
MATHEMATICA
Table[(2 n^3 + 9 n^2 + n + 24)/6, {n, 0, 60}]
CoefficientList[Series[(4 - 10*x + 13*x^2 - 5*x^3)/(x - 1)^4, {x, 0, 60}], x] (* Wesley Ivan Hurt, Aug 29 2015 *)
PROG
(Magma) [(2*n^3+9*n^2+n+24)/6: n in [0..50]]; // Vincenzo Librandi, Dec 27 2010
(PARI) first(m)=vector(m, i, i--; (2*i^3 + 9*i^2 + i + 24) / 6) \\ Anders Hellström, Aug 29 2015
CROSSREFS
Sequence in context: A136391 A105205 A302311 * A359020 A246424 A012776
KEYWORD
nonn,easy
AUTHOR
Reinhard Zumkeller, May 26 2009
STATUS
approved