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.

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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).
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