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.

A324577 a(n) = A025487(n) * A324576(n) = A025487(n) * A276086(A025487(n)).

Original entry on oeis.org

2, 6, 36, 30, 120, 300, 3600, 15000, 210, 672, 1260, 42000, 2940, 28224, 88200, 164640, 288120, 4609920, 216090000, 21176820, 564715200, 2310, 11880, 18480, 4435200, 19404000, 66555720, 44370480000, 50820, 1306800, 2845920, 63748608, 5856903360, 328703760, 306790176000, 12298440, 7906140000, 645668100, 33746919360, 15874550866944
Offset: 1

Views

Author

Antti Karttunen, Mar 09 2019

Keywords

Comments

Note that A324198(A025487(n)) = gcd(A025487(n), A324576(n)) = 1 for all n, because each term of A025487 is a product of primorials.

Crossrefs

Cf. also A324582 (a subsequence).

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; };
    A324577(n) = A025487(n)*A276086(A025487(n));

Formula

a(n) = A025487(n) * A324576(n) = A025487(n) * A276086(A025487(n)).
a(n) = A324580(A025487(n)).