A091718 a(n) = Max{gcd(P(n),P(k)): 0<=k<n}, P = partition function.

1, 1, 1, 1, 1, 1, 5, 11, 15, 7, 14, 11, 1, 15, 22, 77, 33, 77, 35, 33, 99, 6, 5, 45, 22, 42, 70, 22, 55, 12, 22, 33, 69, 10, 363, 1, 77, 215, 385, 147, 231, 22, 891, 25, 41, 6, 98, 21, 55, 22, 363, 759, 63, 385, 71, 11, 6, 55, 220, 17, 1155, 286, 3, 781, 2, 53, 1, 245

Offset

1,7

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10000

Maple

a:= n-> (p-> max(seq(igcd(p(n), p(k)), k=0..n-1)))(combinat[numbpart]):
seq(a(n), n=1..100);  # Alois P. Heinz, Oct 26 2019

Mathematica

m = 100; p = PartitionsP[Range[0, m]]; Table[Max[GCD[p[[n]], p[[1 ;; n - 1]]]], {n, 2, m + 1}] (* Amiram Eldar, May 10 2020 *)

Prog

(PARI) a(n) = my(pn=numbpart(n)); vecmax(vector(n, k, k--; gcd(pn, numbpart(k)))); \\ Michel Marcus, May 10 2020

Crossrefs

Cf. A000041, A091717.

Sequence in context: A079030 A103011 A137002 * A078002 A171418 A213444

Adjacent sequences: A091715 A091716 A091717 * A091719 A091720 A091721

Keyword

nonn

Author

Reinhard Zumkeller, Feb 01 2004

Status

approved