login
A140957
a(n) = A140951(n+1) - A140951(n).
0
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, 1, 1, 2, 8, 32, 256, 32, 8, 2, 1, 1, 4, 16, 64, 512, 64, 16, 4, 1
OFFSET
0,1
COMMENTS
All terms belong to A000079.
Note that the positions of the first occurrences of 4, 8, 16, 32, 64, ... are 3, 6, 10, 15, 21, ...
So a(n) can be displayed as a triangle (hence the tabl keyword), with row sums: 2, 3, 6, 12, 24, 48, ... = A042950.
2;
2, 1;
4, 1, 1;
8, 1, 1, 2;
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.
2;
2;
1, 4, 1;
1, 8, 1;
1, 2, 16, 2, 1;
1, 4, 32, 4, 1;
with row sums: 2, 2, 6, 10, 22, 42, 66, 170, 342, 682, ... = A078008(n+2) = 2*A001045(n+1).
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Paul Curtz, Jul 26 2008
EXTENSIONS
Edited by Michel Marcus, Jan 11 2012
STATUS
approved