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.

A280378 Partial products of A119619.

Original entry on oeis.org

1, 1, 2, 6, 144, 1440, 1036800, 326592000, 1463132160000, 6636767477760000, 24083501823295488000000, 278164446059062886400000000, 133241214725404817086218240000000000, 1851999588197236795571599048704000000000000, 79730449087475946864047275218548293632000000000000
Offset: 1

Views

Author

Jaroslav Krizek, Jan 08 2017

Keywords

Comments

A119619(n) = Product_{d|n} pxi(d), where pxi(m) is the product of totatives of m (A001783).

Crossrefs

Programs

  • Magma
    [&*[&*[&*[h: h in [1..d] | GCD(h,d) eq 1]: d in Divisors(k)]: k in [1..n]]: n in [1..100]]
  • Mathematica
    FoldList[#1 #2 &, Table[Product[Times @@ Select[Range@ d, CoprimeQ[d, #] &], {d, Divisors@ n}], {n, 15}]] (* Michael De Vlieger, Jan 09 2017 *)

Formula

a(n) = Product_{i=1..n} A119619(i).