login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A320373 Number of parts in all partitions of n with largest multiplicity three. 2
3, 0, 4, 7, 13, 14, 27, 33, 55, 72, 107, 137, 196, 250, 344, 442, 588, 750, 982, 1234, 1591, 1992, 2523, 3135, 3944, 4857, 6035, 7408, 9121, 11109, 13599, 16465, 20004, 24122, 29112, 34927, 41952, 50078, 59836, 71169, 84625, 100219, 118716, 140061, 165225 (list; graph; refs; listen; history; text; internal format)
OFFSET

3,1

LINKS

Alois P. Heinz, Table of n, a(n) for n = 3..5000

FORMULA

a(n) ~ log(2) * exp(Pi*sqrt(n/2)) / (Pi * 2^(1/4) * n^(1/4)). - Vaclav Kotesovec, Oct 25 2018

MAPLE

b:= proc(n, i, k) option remember; `if`(n=0, [1, 0], `if`(i<1, 0,

      add((l-> [0, l[1]*j]+l)(b(n-i*j, i-1, k)), j=0..min(n/i, k))))

    end:

a:= n-> (k-> (b(n$2, k)-b(n$2, k-1))[2])(3):

seq(a(n), n=3..60);

MATHEMATICA

b[n_, i_, k_] := b[n, i, k] = If[n == 0, {1, 0}, If[i < 1, {0, 0},        Sum[Function[l, {0, l[[1]] j} + l][b[n - i j, i - 1, k]], {j, 0, Min[n/i, k]}]]];

a[n_] := With[{k = 3}, (b[n, n, k] - b[n, n, k - 1])[[2]]];

a /@ Range[3, 60] (* Jean-Fran├žois Alcover, Dec 13 2020, after Alois P. Heinz *)

CROSSREFS

Column k=3 of A213177.

Sequence in context: A190181 A145092 A210878 * A303274 A199608 A128178

Adjacent sequences:  A320370 A320371 A320372 * A320374 A320375 A320376

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Oct 11 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 24 08:15 EDT 2021. Contains 348217 sequences. (Running on oeis4.)