A266529 Terms of A160552 repeated.
0, 0, 1, 1, 1, 1, 3, 3, 1, 1, 3, 3, 5, 5, 7, 7, 1, 1, 3, 3, 5, 5, 7, 7, 5, 5, 11, 11, 17, 17, 15, 15, 1, 1, 3, 3, 5, 5, 7, 7, 5, 5, 11, 11, 17, 17, 15, 15, 5, 5, 11, 11, 17, 17, 19, 19, 21, 21, 39, 39, 49, 49, 31, 31, 1, 1, 3, 3, 5, 5, 7, 7, 5, 5, 11, 11, 17, 17, 15, 15, 5, 5, 11, 11, 17, 17, 19, 19, 21, 21
Offset: 1
Examples
Written as an irregular triangle in which the row lengths are twice the terms of A011782 the sequence begins: 0,0; 1,1; 1,1,3,3; 1,1,3,3,5,5,7,7; 1,1,3,3,5,5,7,7,5,5,11,11,17,17,15,15; 1,1,3,3,5,5,7,7,5,5,11,11,17,17,15,15,5,5,11,11,17,17,19,19,21,21,39,39,49,49,31,31; ... Row sums give 0 together with A004171.
Links
- Ivan Neretin, Table of n, a(n) for n = 1..8192
Crossrefs
Programs
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Mathematica
Riffle[#, #] &@ Table[SeriesCoefficient[x (1 + 2 x)/(1 + x) + (4 x^2/(1 + 2 x)) (Product[1 + x^(2^k - 1) + 2 x^(2^k), {k, 20}] - 1), {x, 0, n}], {n, 0, 44}] (* Michael De Vlieger, Jan 05 2016, based on Maple by N. J. A. Sloane at A160552 *)
Comments