A164096 Partial sums of A164095.

5, 11, 21, 33, 53, 77, 117, 165, 245, 341, 501, 693, 1013, 1397, 2037, 2805, 4085, 5621, 8181, 11253, 16373, 22517, 32757, 45045, 65525, 90101, 131061, 180213, 262133, 360437, 524277, 720885, 1048565, 1441781, 2097141, 2883573, 4194293, 5767157

Offset: 1

Author

Klaus Brockhaus, Aug 10 2009

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (1, 2, -2).

Crossrefs

Cf. A164095.

Programs

Magma

T:=[ n le 2 select n+4 else 2*Self(n-2): n in [1..38] ]; [ n eq 1 select T[1] else Self(n-1)+T[n]: n in [1..#T]];

Formula

a(n) = 2*a(n-2)+11 for n > 2; a(1) = 5, a(2) = 11.

a(n) = (27-5*(-1)^n)*2^(1/4*(2*n-1+(-1)^n))/2-11.

G.f.: x*(5+6*x)/(1-x-2*x^2+2*x^3).