A140957 - OEIS

%I #13 Feb 22 2020 20:57:36

%S 2,2,1,4,1,1,8,1,1,2,16,2,1,1,4,32,4,1,1,2,8,64,8,2,1,1,4,16,128,16,4,

%T 1,1,2,8,32,256,32,8,2,1,1,4,16,64,512,64,16,4,1

%N a(n) = A140951(n+1) - A140951(n).

%C All terms belong to A000079.

%C Note that the positions of the first occurrences of 4, 8, 16, 32, 64, ... are 3, 6, 10, 15, 21, ...

%C So a(n) can be displayed as a triangle (hence the tabl keyword), with row sums: 2, 3, 6, 12, 24, 48, ... = A042950.

%C 2;

%C 2, 1;

%C 4, 1, 1;

%C 8, 1, 1, 2;

%C It can also be displayed as an irregular table, with length distribution: 1, 1, 3, 3, 5, 5, 7, 7, 9, 9 (doubled A005408) to get palindromic lines.

%C 2;

%C 2;

%C 1,  4,  1;

%C 1,  8,  1;

%C 1,  2, 16,  2,  1;

%C 1,  4, 32,  4,  1;

%C with row sums: 2, 2, 6, 10, 22, 42, 66, 170, 342, 682, ... = A078008(n+2) = 2*A001045(n+1).

%Y Cf. A000079, A042950, A140951, A140643.

%K nonn,tabl

%O 0,1

%A _Paul Curtz_, Jul 26 2008

%E Edited by _Michel Marcus_, Jan 11 2012