Big equivalence classes (A227723) related to subgroups of nimber addition (A190939).

Terms

a(0) =1a(1) =3a(2) =6a(3) =15a(4) =24a(5) =60a(6) =105a(7) =255a(8) =384a(9) =960a(10) =1632a(11) =1680a(12) =4080a(13) =15555a(14) =27030a(15) =65535a(16) =98304a(17) =245760a(18) =417792a(19) =430080a(20) =1044480a(21) =1582080a(22) =3947520a(23) =3982080a(24) =6908160a(25) =6919680a(26) =16776960a(27) =106991625a(28) =267448335a(29) =1019462460