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A164938
a(n) = (n^5 - n)/10, which is always an integer.
4
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
1,2
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
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 *)
CROSSREFS
Cf. A061167.
Sequence in context: A216725 A334038 A320976 * A342112 A050545 A354676
KEYWORD
easy,nonn
AUTHOR
Bill Welsh (bill.welsh.75(AT)gmail.com), Aug 31 2009
EXTENSIONS
More terms from Stefan Steinerberger, Sep 03 2009
STATUS
approved