cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A254436 A component sequence of A254296.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 2, 1, 2, 1, 4, 3, 6, 3, 6, 5, 8, 7, 10, 7, 12, 9, 14, 11, 16, 14, 19, 17, 22, 20, 28, 23, 31, 26, 34, 32, 40, 35, 43, 38, 51, 46, 59, 51, 64, 61, 74, 71, 84, 76, 94, 86, 104, 96, 114, 108, 126, 120, 138, 132, 157, 146, 171
Offset: 1

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Author

Md. Towhidul Islam, Feb 28 2015

Keywords

Comments

This sequence is a component of the formula for counting A254296.
If m=ceiling(log_3(2k)), define n=(3^(m-1)+1)/2+(3^(m-2))-k for k in the range (3^(m-1)+1)/2<=k<=(3^(m-1)-1)/2+(3^(m-2)). Then this sequence gives the first 3^(m-2) terms.

Crossrefs

Formula

If m=ceiling(log_3(2k)), define n=(3^(m-1)+1)/2+(3^(m-2))-k for k in the range (3^(m-1)+1)/2<=k<=(3^(m-1)-1)/2+(3^(m-2)).
Then a(n)=Sum_{d=ceiling((3k+2)/5)..(3^(m-1)-1)/2} Sum_{p=ceiling((d-1)/3..2d-k-1} A254296(p).