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A100242
a(n) = n^5 - n^2*(n^2 - 1)/2.
1
0, 1, 26, 207, 904, 2825, 7146, 15631, 30752, 55809, 95050, 153791, 238536, 357097, 518714, 734175, 1015936, 1378241, 1837242, 2411119, 3120200, 3987081, 5036746, 6296687, 7797024, 9570625, 11653226, 14083551, 16903432, 20157929, 23895450, 28167871
OFFSET
0,3
REFERENCES
T. A. Gulliver, Sequences from Cubes of Integers, Int. Math. Journal, 4 (2003), 439-445.
LINKS
FORMULA
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6); a(0)=0, a(1)=1, a(2)=26, a(3)=207, a(4)=904, a(5)=2825. - Harvey P. Dale, Aug 15 2011
G.f.: (x^5 + 32*x^4 + 66*x^3 + 20*x^2 + x)/(x-1)^6. - Harvey P. Dale, Aug 15 2011
MATHEMATICA
Table[n^5-(n^2 (n^2-1))/2, {n, 0, 40}] (* or *) LinearRecurrence[ {6, -15, 20, -15, 6, -1}, {0, 1, 26, 207, 904, 2825}, 40] (* Harvey P. Dale, Aug 15 2011 *)
PROG
(Magma) [n^5-n^2*(n^2-1)/2: n in [0..50]]; // Vincenzo Librandi, May 15 2011
(PARI) a(n)=n^5-n^2*(n^2-1)/2 \\ Charles R Greathouse IV, Oct 21 2022
CROSSREFS
Sequence in context: A245952 A056026 A159762 * A042310 A213123 A125363
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jan 12 2005
STATUS
approved