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A151675
Row sums of A154685.
3
8, 27, 63, 122, 210, 333, 497, 708, 972, 1295, 1683, 2142, 2678, 3297, 4005, 4808, 5712, 6723, 7847, 9090, 10458, 11957, 13593, 15372, 17300, 19383, 21627, 24038, 26622, 29385, 32333, 35472, 38808, 42347, 46095, 50058, 54242, 58653, 63297
OFFSET
1,1
FORMULA
a(n)=n*(2*n^2+5*n+9)/2 = 4*a(n-1)-6*a(n-2)+4*a(n-3)-a(n-4). G.f.: x*(8-5*x+3*x^2)/(x-1)^4. [From R. J. Mathar, May 31 2009]
a(n) = A162261(n) + 8*n. - L. Edson Jeffery, Oct 12 2012
MATHEMATICA
CoefficientList[Series[(8-5*x+3*x^2)/(x-1)^4, {x, 0, 40}], x] (* Vincenzo Librandi, Jun 30 2012 *)
PROG
(Magma) I:=[8, 27, 63, 122]; [n le 4 select I[n] else 4*Self(n-1)-6*Self(n-2)+4*Self(n-3)-Self(n-4): n in [1..50]]; // Vincenzo Librandi, Jun 30 2012
CROSSREFS
Cf. A162261.
Sequence in context: A141227 A224134 A213488 * A211641 A062686 A093322
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, May 31 2009
EXTENSIONS
Extended by R. J. Mathar, May 31 2009
STATUS
approved