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.

A282940 Largest non-infinitary divisor of A162643(n) having no non-infinitary divisors.

Original entry on oeis.org

2, 3, 6, 8, 6, 10, 5, 14, 8, 6, 22, 15, 24, 7, 10, 26, 30, 21, 8, 34, 24, 15, 38, 40, 27, 42, 30, 46, 24, 14, 33, 10, 54, 56, 58, 39, 11, 62, 42, 66, 70, 24, 21, 74, 30, 51, 78, 40, 54, 82, 13, 57, 86, 35, 88, 30, 94, 24, 14, 66, 40, 102, 69, 104, 106, 110, 56
Offset: 1

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Author

Vladimir Shevelev, Feb 25 2017

Keywords

Comments

Or largest term of A036537 dividing A162643(n) (cf. our comment in A036537).

Crossrefs

Programs

  • Mathematica
    f[p_, e_] := p^(2^Floor[Log2[e + 1]] - 1); s[1] = Nothing; s[n_] := Module[{v = Times @@ f @@@ FactorInteger[n]}, If[v == n, Nothing, v]]; Array[s, 300] (* Amiram Eldar, Apr 29 2024 *)

Formula

a(n) = A036537(m), where m = max{k: A036537(k)|A162643(n)}.
From Amiram Eldar, Apr 29 2024: (Start)
a(n) = A372379(A162643(n)).
Sum_{k=1..n} a(k) ~ ((c-d)/(1-d)^2) * n^2 / 2, where d = A327839 and c = 0.7907361848... is the constant in the asymptotic formula in A372379. (End)

Extensions

More terms from Peter J. C. Moses, Feb 25 2017