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.

A305817 Number of terms of A091206 <= n; Partial sums of A305816.

Original entry on oeis.org

0, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14
Offset: 1

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Author

Antti Karttunen, Jun 15 2018

Keywords

Crossrefs

Programs

  • PARI
    up_to = 65537;
    A305816(n) = (isprime(n)&&polisirreducible(Pol(binary(n))*Mod(1,2)));
    partialsums(f,up_to) = { my(v = vector(up_to), s=0); for(i=1,up_to,s += f(i); v[i] = s); (v); }
    v305817 = partialsums(A305816, up_to);
    A305817(n) = v305817[n];

Formula

a(1) = 0; for n > 1, a(n) = A305816(n-1) + a(n).
For all n >= 1, a(A091206(n)) = n.