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.

Showing 1-2 of 2 results.

A086195 Incorrect version of A380266.

Original entry on oeis.org

1, 2, 3, 1, 1, 1, 1, 11, 13, 14, 5, 16, 17, 6, 19, 23, 4, 25, 13, 9, 14, 29, 5, 31, 33, 34, 37, 38, 13, 40, 41, 46, 47, 48, 49, 51, 26, 53, 27, 55, 4, 57, 29, 59, 30, 61, 31, 9, 13, 22, 67, 68, 23, 14, 71, 24, 73, 74, 5, 76, 77, 26, 79, 17, 43, 87, 22, 89, 9, 91, 23, 94, 95
Offset: 1

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Author

Eric W. Weisstein, Jul 11 2003

Keywords

Comments

Previous name was: Numerators of running averages of A051904.
Due to a bug in the Mathematica code in the World of Mathematics page, the sequence was calculated with running averages over {A051904(1), 1, A051904(2), A051904(3), ... } with the first term removed. See A380266 for the correct sequence. - Amiram Eldar, Jan 18 2025

Examples

			1/2, 2/3, 3/4, 1, 1, 1, 1, 11/9, 13/10, 14/11, ...
		

Crossrefs

Cf. A051904, A086196 (denominators), A380266.

Programs

  • Mathematica
    f[n_] := Min[FactorInteger[n][[;; , 2]]]; f[1] = 0; With[{m = 100}, Numerator[(1 + Accumulate[Array[f, m]]) / Range[2, m + 1]]] (* Amiram Eldar, Jan 18 2025 *)

Formula

a(n) = numerator((1 + Sum_{k=1..n} A051904(k))/(n+1)). - Amiram Eldar, Jan 18 2025

A380267 a(n) is the denominator of the mean value of A051904(k) at the range k = 1..n.

Original entry on oeis.org

1, 2, 3, 1, 1, 1, 1, 4, 3, 10, 11, 4, 13, 14, 5, 8, 17, 3, 19, 10, 7, 11, 23, 4, 25, 26, 3, 28, 29, 10, 31, 32, 33, 34, 35, 18, 37, 19, 39, 20, 41, 3, 43, 22, 45, 23, 47, 24, 49, 10, 17, 52, 53, 18, 11, 56, 19, 58, 59, 4, 61, 62, 21, 16, 13, 33, 67, 17, 69, 7
Offset: 1

Views

Author

Amiram Eldar, Jan 18 2025

Keywords

Crossrefs

Cf. A051904, A380266 (numerators).

Programs

  • Mathematica
    f[n_] := Min[FactorInteger[n][[;;, 2]]]; f[1] = 0; With[{m = 100}, Denominator[Accumulate[Array[f, m]] / Range[m]]]
  • PARI
    lista(nmax) = {my(s = 0); print1(1, ", "); for(n = 2, nmax, s += vecmin(factor(n)[,2]);  print1(denominator(s/n), ", "));}

Formula

a(n) = denominator((Sum_{k=1..n} A051904(k))/n).
Showing 1-2 of 2 results.