Number of subsets of [n] whose sum is a triangular number.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =7a(5) =11a(6) =18a(7) =29a(8) =49a(9) =85a(10) =151a(11) =271a(12) =493a(13) =904a(14) =1674a(15) =3118a(16) =5835a(17) =10966a(18) =20698a(19) =39187a(20) =74413a(21) =141684a(22) =270386a(23) =517110a(24) =990889a(25) =1902108a(26) =3657241a(27) =7042490a(28) =13580079a(29) =26220417