A026064 a(n) = (d(n)-r(n))/2, where d = A026063 and r is the periodic sequence with fundamental period (1,1,0,1).

35, 59, 90, 127, 172, 225, 287, 357, 437, 527, 628, 739, 862, 997, 1145, 1305, 1479, 1667, 1870, 2087, 2320, 2569, 2835, 3117, 3417, 3735, 4072, 4427, 4802, 5197, 5613, 6049, 6507, 6987, 7490, 8015, 8564, 9137, 9735, 10357, 11005, 11679, 12380, 13107, 13862, 14645, 15457, 16297

Offset

6,1

Links

Table of n, a(n) for n=6..53.

Index entries for linear recurrences with constant coefficients, signature (3,-3,1,1,-3,3,-1).

Formula

a(n)=(n + 6)*(n^2 + 30*n + 71)/12 - 0.375 + 0.125*( - 1)^n - 0.25*cos(n*Pi/2) [From Richard Choulet, Dec 13 2008]

G.f.: x^6*( 35-46*x+18*x^2-x^3-33*x^4-17*x^6+46*x^5 ) / ( (1+x)*(x^2+1)*(x-1)^4 ). - R. J. Mathar, Jun 23 2013

Crossrefs

Sequence in context: A244057 A219457 A343099 * A338244 A250764 A362198

Adjacent sequences: A026061 A026062 A026063 * A026065 A026066 A026067

Keyword

nonn,easy

Author

Clark Kimberling

Status

approved