A390507 - OEIS

%I #12 Dec 27 2025 19:21:55

%S 1,2,1,3,3,2,2,3,4,3,3,5,3,3,1,4,4,3,4,6,4,4,4,5,6,5,3,5,4,2,2,3,5,4,

%T 4,6,4,4,5,6,7,6,4,6,5,3,3,6,6,5,6,8,6,6,4,5,6,5,4,6,3,3,2,4,4,3,5,7,

%U 5,5,5,6,7,6,4,6,5,3,4,7,7,6,7,9,7,7

%N a(n) = number of 1's in A390505(n).

%F a(n) = A007953(A390505(n)).

%e A390505(20) = 10111011, so a(2) = 6.

%t f[w_] := StringJoin[Map[IntegerString[Length[#], 2] <> ToString[#[[1]]] &, Split[Characters[w]]]];

%t s[n_] := Map[StringJoin[Map[ToString, Rest[IntegerDigits[#, 2]]]] &, Range[2, 2^(n + 1) - 1]];

%t m = Map[f, s[6]]   (* A390505 *)

%t m1 = ToExpression /@ Characters /@ m;u = Map[Length, m1]

%t Table[Count[m1[[n]], 1], {n, 1, 120}]  (* A390507 *)

%t (* _Peter J. C. Moses_, Nov 05 2025 *)

%Y Cf. A007953, A390505, A390506.

%K nonn,base

%O 1,2

%A _Clark Kimberling_, Dec 02 2025