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.

A351092 a(n) = Product_{d|A000265(n)} A019565(A289814(d)); a product obtained from the 2-digits present in ternary expansions of the odd divisors of n.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 3, 1, 1, 2, 2, 1, 1, 3, 6, 1, 6, 1, 5, 2, 15, 2, 10, 1, 30, 1, 1, 3, 2, 6, 1, 1, 6, 6, 36, 1, 1, 5, 1, 2, 2, 15, 3, 2, 30, 10, 10, 1, 15, 30, 90, 1, 30, 1, 28, 3, 35, 2, 14, 6, 21, 1, 105, 1, 28, 6, 7, 6, 210, 36, 42, 1, 35, 1, 3150, 5, 420, 1, 105, 2, 1, 2, 2, 15, 12, 3, 6, 2, 6, 30, 3, 10, 1, 10
Offset: 1

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Author

Antti Karttunen, Jan 31 2022

Keywords

Crossrefs

Cf. A000265, A019565, A289814, A351082, A351091, A351094 (rgs-transform).

Programs

  • PARI
    A019565(n) = { my(m=1, p=1); while(n>0, p = nextprime(1+p); if(n%2, m *= p); n >>= 1); (m); };
    A289814(n) = { my(d=digits(n, 3)); fromdigits(vector(#d, i, if (d[i]==2, 1, 0)), 2); };
    A351092(n) = { my(m=1); fordiv(n>>valuation(n,2),d,m *= A019565(A289814(d))); (m); };

Formula

a(n) = A351082(A000265(n)).