Number of (w,x,y,z) with all terms in {1,...,n} and 2w+2x=3y+3z.

Terms

a(0) =0a(1) =0a(2) =2a(3) =5a(4) =11a(5) =27a(6) =42a(7) =68a(8) =106a(9) =149a(10) =201a(11) =279a(12) =354a(13) =452a(14) =572a(15) =701a(16) =845a(17) =1031a(18) =1212a(19) =1428a(20) =1676a(21) =1937a(22) =2219a(23) =2559a(24) =2892a(25) =3272a(26) =3694a(27) =4133a(28) =4599a(29) =5139