A262567 a(n) = A002703(n)/2.

0, 0, 0, 1, 3, 7, 12, 23, 44, 81, 150, 281, 528, 991, 1871, 3541, 6719, 12787, 24384, 46599, 89240, 171196, 328959, 633101, 1220159, 2354687, 4549752, 8801161, 17043505, 33038207, 64103988, 124491775, 241969988, 470681347, 916259631, 1784921473, 3479467176, 6787108712, 13247128044, 25870861823

Offset: 3

Author

N. J. A. Sloane, Oct 20 2015

Keywords

• nonn

Comments

A002703 is somewhat mysterious. Having four versions (A002703, this sequence, A262568, A262569) instead of one increases the chance that one of them will be found in a different context.

Links

• Alexander Rosa and Štefan Znám, A combinatorial problem in the theory of congruences. (Russian), Mat.-Fys. Casopis Sloven. Akad. Vied 15 1965 49-59. [Annotated scanned copy]

Crossrefs

Cf. A002703, A262568, A262569.

Tables 1 and 2 of the first Rosa-Znám 1965 paper are A053632 and A178666 respectively.

Programs

Maple

See A262568.

Extensions

More terms from R. J. Mathar, Oct 21 2015