Fourth-order spt function.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =9a(5) =45a(6) =166a(7) =505a(8) =1341a(9) =3223a(10) =7149a(11) =14916a(12) =29480a(13) =55902a(14) =101892a(15) =180245a(16) =309297a(17) =518859a(18) =849563a(19) =1366441a(20) =2154789a(21) =3348972a(22) =5119981a(23) =7733835a(24) =11520100a(25) =16985374a(26) =24746334a(27) =35735413a(28) =51073008a(29) =72432093