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.

A350063 a(n) is the smallest number with the same prime signature as A322993(n), with a(1) = 0.

Original entry on oeis.org

0, 1, 1, 2, 1, 2, 1, 2, 2, 4, 1, 2, 1, 2, 2, 6, 1, 2, 1, 2, 4, 6, 1, 2, 2, 6, 2, 6, 1, 6, 1, 2, 2, 6, 2, 8, 1, 2, 6, 6, 1, 2, 1, 2, 2, 24, 1, 2, 2, 4, 6, 2, 1, 2, 4, 2, 6, 12, 1, 2, 1, 6, 2, 12, 2, 6, 1, 6, 2, 2, 1, 6, 1, 6, 2, 6, 2, 6, 1, 2, 6, 6, 1, 12, 6, 30, 24, 24, 1, 12, 4, 6, 12, 60, 6, 6, 1, 4, 6, 6, 1
Offset: 1

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Author

Antti Karttunen, Jan 29 2022

Keywords

Crossrefs

Cf. A000265, A046523, A156552, A322993, A350062, A350064, A350065 (rgs-transform).

Programs

  • PARI
    A000265(n) = (n>>valuation(n,2));
    A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523
    A156552(n) = { my(f = factor(n), p, p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res };
    A350063(n) = if(1==n,0,A046523(A000265(A156552(n))));

Formula

a(1) = 0; for n > 1, a(n) = A046523(A322993(n)) = A046523(A000265(A156552(n))).