Number of compositions [p(1), p(2), ..., p(k)] of n such that p(j) <= 2*p(j-1) and p(j-1) <= 2*p(j).
A224957
Number of compositions [p(1), p(2), ..., p(k)] of n such that p(j) <= 2*p(j-1) and p(j-1) <= 2*p(j).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =4a(4) =6a(5) =11a(6) =19a(7) =31a(8) =54a(9) =92a(10) =154a(11) =266a(12) =454a(13) =771a(14) =1319a(15) =2249a(16) =3834a(17) =6550a(18) =11176a(19) =19069a(20) =32558a(21) =55567a(22) =94838a(23) =161891a(24) =276325a(25) =471659a(26) =805102a(27) =1374234a(28) =2345724a(29) =4004031
External references
- oeis: A224957