Number of subsets of the first n nonzero n-gonal numbers whose sum is a nonzero n-gonal number.

Terms

a(0) =3a(1) =4a(2) =5a(3) =7a(4) =7a(5) =10a(6) =11a(7) =18a(8) =20a(9) =23a(10) =31a(11) =63a(12) =77a(13) =127a(14) =212a(15) =332a(16) =569a(17) =1034a(18) =1749a(19) =2961a(20) =5236a(21) =9319a(22) =16524a(23) =28583a(24) =53618a(25) =96310a(26) =174573a(27) =309344a(28) =584500a(29) =1077230