OFFSET
0,1
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
Yang-Hui He and John McKay, Sporadic and Exceptional, arXiv:1505.06742 [math.AG], 2015.
Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).
FORMULA
a(n) = (24 + 250*n + 125*n^2 + 20*n^3 + n^4)/12 for n > 0. - Colin Barker, Apr 15 2016
From G. C. Greubel, Mar 24 2022: (Start)
a(n) = 2*[n=0] + A257601(n).
E.g.f.: 2 + (1/12)*(24 + 396*x + 192*x^2 + 26*x^3 + x^4)*exp(x). (End)
MATHEMATICA
CoefficientList[Series[(4 +15x -35x^2 +20x^3 -2x^5)/(1-x)^5, {x, 0, 50}], x] (* Vincenzo Librandi, Jun 08 2015
PROG
(Magma) I:=[4, 35, 100, 210, 380, 627]; [n le 6 select I[n] else 5*Self(n-1)-10*Self(n-2)+10*Self(n-3)-5*Self(n-4)+Self(n-5): n in [1..51]]; // Vincenzo Librandi, Jun 08 2015
(PARI) Vec((4+15*x-35*x^2+20*x^3-2*x^5)/(1-x)^5 + O(x^50)) \\ Colin Barker, Apr 15 2016
(Sage) [2*bool(n==0) + (24+250*n+125*n^2+20*n^3+n^4)/12 for n in (0..50)] # G. C. Greubel, Mar 24 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jun 07 2015
STATUS
approved