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.

A304110 a(n) is the number of terms of A304107 <= n; Partial sums of A304109.

Original entry on oeis.org

1, 2, 3, 3, 3, 4, 5, 5, 6, 6, 7, 7, 8, 9, 9, 9, 9, 10, 11, 11, 11, 12, 13, 13, 14, 15, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 20, 21, 21, 21, 22, 22, 23, 23, 23, 24, 25, 25, 26, 27, 27, 27, 28, 28, 29, 29, 29, 30, 31, 31, 32, 33, 33, 33, 33, 34, 35, 35, 35, 36, 37, 37, 38, 39, 39, 39, 40, 40, 41, 41, 41, 42, 43, 43, 43, 44
Offset: 1

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Author

Antti Karttunen, May 13 2018

Keywords

Comments

Question: Does lim_{n -> inf} a(n)/n converge to 1/2 ? See also A304111.

Crossrefs

Programs

  • PARI
    up_to = 128;
    A304109(n) = { my(fm=factor(Pol(binary(n))*Mod(1, 2))); for(k=1, #fm~, if(fm[k, 2] > 1, return(0))); (1); };
    prepare_v304110(up_to) = { my(v=vector(up_to), c=0); for(n=1, up_to, c += A304109(n); v[n] = c); (v); };
    v304110 = prepare_v304110(up_to);
    A304110(n) = v304110[n];

Formula

a(1) = 1; for n > 1, a(n) = A304109(n) + a(n-1).