Number of 4-gonal compositions of n into positive parts.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =4a(6) =10a(7) =16a(8) =31a(9) =40a(10) =68a(11) =80a(12) =125a(13) =140a(14) =206a(15) =224a(16) =315a(17) =336a(18) =456a(19) =480a(20) =633a(21) =660a(22) =850a(23) =880a(24) =1111a(25) =1144a(26) =1420a(27) =1456a(28) =1781a(29) =1820