A164938 a(n) = (n^5 - n)/10, which is always an integer.

0, 3, 24, 102, 312, 777, 1680, 3276, 5904, 9999, 16104, 24882, 37128, 53781, 75936, 104856, 141984, 188955, 247608, 319998, 408408, 515361, 643632, 796260, 976560, 1188135, 1434888, 1721034, 2051112, 2429997, 2862912, 3355440, 3913536

Offset: 1

Author

Bill Welsh (bill.welsh.75(AT)gmail.com), Aug 31 2009

Keywords

• easy
• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..10000
• Index entries for linear recurrences with constant coefficients, signature (6,-15,20,-15,6,-1).

Crossrefs

Cf. A061167.

Programs

Mathematica

Table[(n^5 - n)/10, {n, 1, 50}] (* Stefan Steinerberger, Sep 03 2009 *)
LinearRecurrence[{6,-15,20,-15,6,-1},{0,3,24,102,312,777},50] (* Harvey P. Dale, Jan 14 2012 *)

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) for n > 6. - Harvey P. Dale, Jan 14 2012

G.f.: (3*(x^3+2*x^2+x))/(x-1)^6. - Harvey P. Dale, Jan 14 2012

a(n) = A061167(n)/10. - Michel Marcus, Sep 04 2013

E.g.f.: exp(x)*x^2*(15 + 25*x + 10*x^2 + x^3)/10. - Stefano Spezia, Dec 27 2021

Extensions

More terms from Stefan Steinerberger, Sep 03 2009