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 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 (list; table; graph; refs; listen; history; text; internal format)
 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). LINKS CROSSREFS Cf. A000079, A042950, A140951, A140643. Sequence in context: A106641 A191785 A320500 * A197250 A275578 A112085 Adjacent sequences:  A140954 A140955 A140956 * A140958 A140959 A140960 KEYWORD nonn,tabl AUTHOR Paul Curtz, Jul 26 2008 EXTENSIONS Edited by Michel Marcus, Jan 11 2012 STATUS approved

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Last modified July 24 11:42 EDT 2021. Contains 346273 sequences. (Running on oeis4.)