A026061 a(n) = (d(n)-r(n))/2, where d = A026060 and r is the periodic sequence with fundamental period (1,0,0,0).

22, 40, 63, 92, 127, 170, 220, 278, 344, 420, 505, 600, 705, 822, 950, 1090, 1242, 1408, 1587, 1780, 1987, 2210, 2448, 2702, 2972, 3260, 3565, 3888, 4229, 4590, 4970, 5370, 5790, 6232, 6695, 7180, 7687, 8218, 8772, 9350, 9952, 10580, 11233, 11912, 12617, 13350, 14110, 14898

Offset: 5

Author

Clark Kimberling

Keywords

• nonn
• easy

Links

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

Formula

G.f.: x^5*( 22-26*x+9*x^2+x^3+28*x^5-10*x^6-22*x^4 ) / ( (1+x)*(x^2+1)*(x-1)^4 ). - R. J. Mathar, Jun 23 2013