a(n) = number of subsets S of {1,2,...,n} having more than 1 element such that (sum of least two elements of S) < max(S).

A357283

a(n) = number of subsets S of {1,2,...,n} having more than 1 element such that (sum of least two elements of S) < max(S).

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =2a(5) =8a(6) =26a(7) =68a(8) =166a(9) =376a(10) =826a(11) =1756a(12) =3678a(13) =7584a(14) =15522a(15) =31524a(16) =63782a(17) =128552a(18) =258602a(19) =519212a(20) =1041454a(21) =2086960a(22) =4180018a(23) =8368180a(24) =16748598a(25) =33513528a(26) =67051578a(27) =134135868a(28) =268320830a(29) =536707136

External references