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.

A324529 a(n) = lcm(sigma(n), pod(n)) where sigma(k) = the sum of divisors of k (A000203) and pod(n) = the product of divisors of k (A007955).

Original entry on oeis.org

1, 6, 12, 56, 30, 36, 56, 960, 351, 900, 132, 12096, 182, 1176, 1800, 31744, 306, 75816, 380, 168000, 14112, 4356, 552, 1658880, 3875, 14196, 29160, 21952, 870, 810000, 992, 2064384, 17424, 31212, 58800, 917070336, 1406, 21660, 85176, 23040000, 1722, 6223392
Offset: 1

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Author

Jaroslav Krizek, Mar 05 2019

Keywords

Examples

			For n=4: a(4) = lcm(sigma(4), pod(4)) = lcm(7, 8) = 56.
		

Crossrefs

Programs

  • Magma
    [LCM(SumOfDivisors(n), &*[d: d in Divisors(n)]): n in [1.. 1000]]
    
  • PARI
    a(n) = my(d=divisors(n)); lcm(vecsum(d), vecprod(d)); \\ Michel Marcus, Mar 05 2019

Formula

a(n) = pod(n) for numbers n in A145551.
a(n) = sigma(n) * pod(n) for numbers n in A014567.