A154796 Even partition numbers of odd numbers.

30, 56, 176, 490, 792, 1958, 3010, 6842, 89134, 124754, 451276, 614154, 831820, 2012558, 8118264, 13848650, 133230930, 214481126, 271248950, 541946240, 851376628, 1327710076, 3163127352, 4835271870, 5964539504, 7346629512

Offset

1,1

Comments

Even numbers in A058695.

Links

Alois P. Heinz, Table of n, a(n) for n = 1..1000

Example

The even number 30 is in the sequence as the partition number of the odd number 9. - Emeric Deutsch, Aug 02 2009

Maple

aa:= proc(n, i) if n=0 then 1 elif n<0 or i=0 then 0 else aa(n, i):= aa(n, i-1) +aa(n-i, i) fi end: a:= proc(n) local k; if n>1 then a(n-1) fi; for k from `if`(n=1, 1, b(n-1)+2) by 2 while irem(aa(k, k), 2)=1 do od; b(n):= k; aa(k, k) end: seq(a(n), n=1..40); # Alois P. Heinz, Jul 28 2009
with(combinat): a := proc (n) if `mod`(numbpart(2*n-1), 2) = 0 then numbpart(2*n-1) else end if end proc: seq(a(n), n = 1 .. 70); # Emeric Deutsch, Aug 02 2009

Mathematica

Reap[Do[If[EvenQ[p = PartitionsP[n]], Sow[p]], {n, 1, 199, 2}]][[2, 1]] (* Jean-François Alcover, Nov 11 2015 *)
Select[PartitionsP[Range[1, 201, 2]], EvenQ] (* Harvey P. Dale, Apr 03 2019 *)

Prog

(PARI) lista(nn) = for (n=1, nn, if (((p = numbpart(2*n+1)) % 2) == 0, print1(p, ", "))); \\ Michel Marcus, Dec 19 2016

Crossrefs

Cf. A000041, A005408, A058695, A154795, A154797, A154798.

Sequence in context: A029713 A154599 A048451 * A350316 A248572 A248739

Adjacent sequences: A154793 A154794 A154795 * A154797 A154798 A154799

Keyword

nonn

Author

Omar E. Pol, Jan 26 2009

Extensions

More terms from Alois P. Heinz, Jul 28 2009

Status

approved