A026044 a(n) = (d(n)-r(n))/2, where d = A026043 and r is the periodic sequence with fundamental period (1,1,0,0).

22, 33, 49, 70, 97, 132, 176, 229, 292, 367, 455, 556, 671, 802, 950, 1115, 1298, 1501, 1725, 1970, 2237, 2528, 2844, 3185, 3552, 3947, 4371, 4824, 5307, 5822, 6370, 6951, 7566, 8217, 8905, 9630, 10393, 11196, 12040, 12925, 13852, 14823, 15839, 16900, 18007, 19162, 20366, 21619, 22922, 24277

Offset

5,1

Links

Table of n, a(n) for n=5..54.

Index entries for linear recurrences with constant coefficients, signature (4,-7,8,-7,4,-1).

Formula

a(n)=(n + 5)*(2*n^2 + 11*n + 54)/12 - 1/4 - (1/4)*cos(Pi*n/2) - (1/4)*sin(Pi*n/2) [From Richard Choulet, Dec 13 2008]

G.f. x^5*( 22-55*x+71*x^2-71*x^3+50*x^4-15*x^5 ) / ( (x^2+1)*(x-1)^4 ). - R. J. Mathar, Jun 22 2013

Mathematica

LinearRecurrence[{4, -7, 8, -7, 4, -1}, {22, 33, 49, 70, 97, 132}, 60] (* Harvey P. Dale, Apr 27 2019 *)

Crossrefs

Sequence in context: A067035 A074054 A067287 * A120146 A138840 A257473

Adjacent sequences: A026041 A026042 A026043 * A026045 A026046 A026047

Keyword

nonn

Author

Clark Kimberling

Status

approved