[go: up one dir, main page]

login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A320607
Number of parts in all partitions of n in which no part occurs more than four times.
3
1, 3, 6, 12, 15, 29, 41, 65, 91, 132, 179, 257, 339, 465, 616, 823, 1062, 1402, 1790, 2320, 2939, 3750, 4701, 5946, 7398, 9243, 11428, 14161, 17368, 21372, 26056, 31823, 38596, 46838, 56499, 68208, 81868, 98292, 117489, 140390, 167068, 198796, 235655, 279239
OFFSET
1,2
LINKS
FORMULA
a(n) ~ 3^(1/4) * log(5) * exp(2*Pi*sqrt(2*n/15)) / (2^(5/4) * 5^(1/4) * Pi * n^(1/4)). - Vaclav Kotesovec, Oct 18 2018
MAPLE
b:= proc(n, i) option remember; `if`(n=0, [1, 0], `if`(2*i*(i+1)<n, 0, add(
(l-> [0, l[1]*j]+l)(b(n-i*j, min(n-i*j, i-1))), j=0..min(n/i, 4))))
end:
a:= n-> b(n$2)[2]:
seq(a(n), n=1..50);
MATHEMATICA
Table[Length[Flatten[Select[IntegerPartitions[n], Max[Tally[#][[All, 2]]]<5&]]], {n, 50}] (* Harvey P. Dale, May 18 2020 *)
CROSSREFS
Column k=4 of A210485.
Cf. A035959.
Sequence in context: A290258 A277335 A267353 * A281063 A032602 A116593
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 17 2018
STATUS
approved