A373627 Expansion of 1 / ( (1 - 8*x^4) * (1 - x/(1 - 8*x^4)^(1/4)) ).

1, 1, 1, 1, 9, 11, 13, 15, 81, 109, 141, 177, 729, 1041, 1429, 1901, 6561, 9759, 13981, 19419, 59049, 90483, 133893, 192327, 531441, 832911, 1264173, 1865539, 4782969, 7628799, 11816853, 17828163, 43046721, 69620541, 109646397, 168500385, 387420489, 633634769

Offset

0,5

Links

Table of n, a(n) for n=0..37.

Formula

a(4*n) = 9^n for n >= 0.

a(n) = Sum_{k=0..floor(n/4)} 8^k * binomial(n/4,k).

a(n) == 1 (mod 2).

Prog

(PARI) a(n) = sum(k=0, n\4, 8^k*binomial(n/4, k));

Crossrefs

Cf. A373509, A373583.

Sequence in context: A251394 A155877 A214865 * A225557 A120177 A291350

Adjacent sequences: A373623 A373624 A373626 * A373628 A373629 A373630

Keyword

nonn

Author

Seiichi Manyama, Jun 11 2024

Status

approved