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.

A319708 a(n) = Product_{d|n, dA276086(d).

Original entry on oeis.org

1, 2, 2, 6, 2, 36, 2, 54, 12, 108, 2, 1620, 2, 60, 216, 810, 2, 5400, 2, 43740, 120, 540, 2, 607500, 36, 300, 360, 40500, 2, 21870000, 2, 182250, 1080, 2700, 360, 151875000, 2, 1500, 600, 246037500, 2, 101250000, 2, 5467500, 972000, 13500, 2, 85429687500, 20, 6075000, 5400, 5062500, 2, 2531250000, 3240, 3417187500, 3000, 67500, 2
Offset: 1

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Author

Antti Karttunen, Oct 03 2018

Keywords

Crossrefs

Cf. A276085, A276086, A319709 (rgs-transform).
Cf. A293214, A293221, A293222, A300834 for similar constructions for other bases.

Programs

  • PARI
    A276086(n) = { my(i=0,m=1,pr=1,nextpr); while((n>0),i=i+1; nextpr = prime(i)*pr; if((n%nextpr),m*=(prime(i)^((n%nextpr)/pr));n-=(n%nextpr));pr=nextpr); m; };
    A319708(n) = { my(m=1); fordiv(n, d, if(dA276086(d))); (m); };

Formula

a(n) = Product_{d|n, dA276086(d).
For all n >= 1:
A276085(a(n)) = A001065(n).
A001222(a(n)) = A319713(n).