A026050 a(n) = (d(n)-r(n))/2, where d = A026049 and r is the periodic sequence with fundamental period (1,0,0,1).

59, 78, 102, 132, 170, 217, 273, 339, 417, 508, 612, 730, 864, 1015, 1183, 1369, 1575, 1802, 2050, 2320, 2614, 2933, 3277, 3647, 4045, 4472, 4928, 5414, 5932, 6483, 7067, 7685, 8339, 9030, 9758, 10524, 11330, 12177, 13065, 13995, 14969, 15988, 17052, 18162, 19320, 20527, 21783, 23089

Offset: 7

Author

Clark Kimberling

Keywords

• nonn

Formula

Conjecture: G.f. x^7*( 59-158*x+203*x^2-202*x^3+145*x^4-45*x^5 ) / ( (x^2+1)*(x-1)^4 ). - R. J. Mathar, Jun 22 2013