A101693 A modular binomial sum transform of 2^n.

1, 1, 5, 1, 21, 1, 5, 17, 341, 1, 5, 17, 85, 257, 1285, 4369, 87381, 1, 5, 17, 85, 257, 1285, 4369, 21845, 65537, 327685, 1114129, 5570645, 16843009, 84215045, 286331153, 5726623061, 1, 5, 17, 85, 257, 1285, 4369, 21845, 65537, 327685, 1114129, 5570645

Offset

0,3

Comments

a(2^n)=A101694(n); b(2^n+1) is 5,1,1,1,....

Links

Table of n, a(n) for n=0..44.

Formula

a(n)=sum{k=0..n, mod(binomial(2n-2, k), 2)2^k}

Mathematica

Table[Sum[Mod[Binomial[2n-2, k], 2]2^k, {k, 0, n}], {n, 0, 50}] (* Harvey P. Dale, Nov 23 2019 *)

Crossrefs

Cf. A001045.

Sequence in context: A070729 A348501 A296306 * A063476 A126325 A278544

Adjacent sequences: A101690 A101691 A101692 * A101694 A101695 A101696

Keyword

easy,nonn

Author

Paul Barry, Dec 11 2004

Status

approved