A026924 - OEIS

%I #9 Aug 22 2019 08:18:44

%S 0,0,0,1,0,1,1,3,3,5,5,8,8,12,13,18,19,24,26,33,35,43,46,55,59,69,74,

%T 86,91,104,111,126,134,150,159,177,187,207,219,241,254,277,292,318,

%U 334,362,380,410,430,462,484,519,542,579,605

%N Number of partitions of n into an odd number of parts, the greatest being 4; also, a(n+7) = number of partitions of n+3 into an even number of parts, each <=4.

%H R. J. Mathar, <a href="/A026924/b026924.txt">Table of n, a(n) for n = 1..394</a>

%F a(n) + A026928(n) = A026810(n). - _R. J. Mathar_, Aug 22 2019

%p A026924 := proc(n)

%p     local a,p1,p2,p3,p4 ;

%p     a := 0 ;

%p     for p1 from 0 to n do

%p         for p2 from 0 to (n-p1)/2 do

%p             for p3 from op(1+modp(n-p1-2*p2,4),[0,3,2,1]) to (n-p1-2*p2)/3 by 4 do

%p                 p4 := (n-p1-2*p2-3*p3)/4 ;

%p                 if type(p4,'integer') and p4 >=1 and type(p1+p2+p3+p4,'odd') then

%p                     a := a+1 ;

%p                 end if:

%p             end do:

%p         end do:

%p     end do:

%p     a;

%p end proc: # _R. J. Mathar_, Aug 22 2019

%Y 4th column of A026920.

%K nonn

%O 1,8

%A _Clark Kimberling_