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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.

A276157 a(n) = {greatest primorial less than or equal to n} divided by {greatest primorial number which divides n} = A260188(n)/A053589(n).

Original entry on oeis.org

1, 1, 2, 1, 2, 1, 6, 3, 6, 3, 6, 1, 6, 3, 6, 3, 6, 1, 6, 3, 6, 3, 6, 1, 6, 3, 6, 3, 6, 1, 30, 15, 30, 15, 30, 5, 30, 15, 30, 15, 30, 5, 30, 15, 30, 15, 30, 5, 30, 15, 30, 15, 30, 5, 30, 15, 30, 15, 30, 1, 30, 15, 30, 15, 30, 5, 30, 15, 30, 15, 30, 5, 30, 15, 30, 15, 30, 5, 30, 15, 30
Offset: 1

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Author

Antti Karttunen, Aug 30 2016

Keywords

Crossrefs

Cf. A060735 (positions of ones).

Programs

  • Mathematica
    Table[(j = #; While[! Divisible[n, Times @@ Prime@ Range@ j], j--]; (Times @@ Prime@ Range@ #)/(Times @@ Prime@ Range@ j)) &@ (k = 0; While[Times @@ Prime@ Range[k + 1] <= n, k++]; k), {n, 120}] (* Michael De Vlieger, Aug 30 2016 *)
  • Scheme
    (define (A276157 n) (/ (A260188 n) (A053589 n)))

Formula

a(n) = A260188(n)/A053589(n).