A110436 A weighted sum of Jacobi function values.

1, 3, 7, 13, 31, 63, 105, 255, 511, 869, 2047, 3963, 7021, 16383, 32767, 56141, 125811, 262143, 449325, 1048575, 2097151, 3459945, 8388607, 16645111, 28760685, 67108863, 129822555, 230087021, 536870911, 1073741823, 1823791973

Offset

1,2

Comments

It would appear that a(n)=2^m-1 if 2n+1 is prime.

Links

Table of n, a(n) for n=1..31.

Formula

a(n)=sum{k=0..n, abs(Jacobi(n-k, 2k+1))2^k}

Crossrefs

Cf. A005097, A110437.

Sequence in context: A119962 A333877 A220746 * A126879 A247895 A336688

Adjacent sequences: A110433 A110434 A110435 * A110437 A110438 A110439

Keyword

easy,nonn

Author

Paul Barry, Jul 20 2005

Status

approved