A145850 a(n) = A145818(2n-1).

1, 17, 65, 81, 257, 273, 321, 337, 1025, 1041, 1089, 1105, 1281, 1297, 1345, 1361, 4097, 4113, 4161, 4177, 4353, 4369, 4417, 4433, 5121, 5137, 5185, 5201, 5377, 5393, 5441, 5457, 16385, 16401, 16449, 16465, 16641, 16657, 16705, 16721, 17409, 17425, 17473, 17489, 17665, 17681

Offset

1,2

Comments

Every positive odd integer m == 3 (mod 16) is a unique sum of the form a(s) + 2a(t), while other odd integers are not expressible in such form.

Links

Table of n, a(n) for n=1..46.

Formula

If f(x) = Sum_{n>=1} x^a(n), abs(x) < 1, then f(x)*f(x^2) = x^3/(1-x^16).

Crossrefs

Bisection of A145818.

Cf. A145812, A145849.

Sequence in context: A172076 A063522 A244973 * A125992 A363714 A054402

Adjacent sequences: A145847 A145848 A145849 * A145851 A145852 A145853

Keyword

nonn

Author

Vladimir Shevelev, Oct 21 2008

Extensions

More terms from Michel Marcus, Dec 15 2018

Status

approved