A156537 a(n), a(n+1), a(n+2), for n=2,5,8,11,... are respectively the numbers of representations of the integers 2^k-2, 2^k, 2^k+2, where k=(n+4)/3, by unordered sums of two numbers of A156284.

0, 0, 1, 1, 0, 1, 2, 0, 1, 2, 0, 3, 3, 0, 2, 5, 0, 4, 6, 0, 9, 19, 0, 8, 11, 0, 23, 51, 0, 27, 44, 0, 70, 207, 0, 80, 92, 0, 217, 399, 0, 279, 444, 0, 685, 1653, 0, 630, 1010, 0, 2137, 4893, 0, 3068, 3683, 0, 6855

Offset: 2

Author

Vladimir Shevelev, Feb 09 2009, Feb 14 2009

Keywords

• nonn

Comments

According to the construction of A156284, a_(3n)=0, n>=1. These terms may be called "wells". The growth of the depth of the "wells" is O(2^(n/3)log(n)/n^2).

Crossrefs

Cf. A156284, A002375.

Extensions

Edited by N. J. A. Sloane, Feb 14 2009

Additional terms from Vladimir Shevelev, Mar 19 2009