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.

A365461 Sum of digits when A181821(n) is written in primorial base (A049345).

Original entry on oeis.org

1, 1, 2, 1, 2, 2, 4, 1, 2, 4, 2, 2, 4, 4, 4, 1, 6, 6, 6, 4, 8, 4, 6, 2, 2, 8, 6, 2, 12, 6, 16, 1, 6, 10, 4, 6, 16, 10, 8, 4, 10, 6, 10, 4, 12, 10, 6, 2, 8, 6, 10, 8, 12, 10, 8, 8, 20, 10, 18, 2, 26, 14, 8, 1, 12, 12, 22, 10, 20, 12, 28, 6, 28, 14, 10, 10, 6, 8, 34, 4, 8, 18, 38, 4, 10, 14, 20, 6, 52, 10, 12, 10, 24
Offset: 1

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Author

Antti Karttunen, Sep 15 2023

Keywords

Comments

Minimal number of primorials (A002110) that add to A181821(n).

Crossrefs

Programs

  • PARI
    A181821(n) = { my(f=factor(n),p=0,m=1); forstep(i=#f~,1,-1,while(f[i,2], f[i,2]--; m *= (p=nextprime(p+1))^primepi(f[i,1]))); (m); };
    A276150(n) = { my(s=0, p=2, d); while(n, d = (n%p); s += d; n = (n-d)/p; p = nextprime(1+p)); (s); };
    A365461(n) = A276150(A181821(n));

Formula

a(n) = A276150(A181821(n)).
a(n) = A324888(A122111(n)).
a(n) >= A365460(n).