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A012257 Table: row 1 is {1,1}; if row n is {r_1, ..., r_k} then row n+1 is {r_k 1's, r_{k-1} 2's, r_{k-2} 3's, etc.}. +0
7
1, 1, 1, 2, 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 2, 2, 3, 4, 1, 1, 1, 1, 2, 2, 2, 3, 3, 4, 4, 5, 6, 7, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 9, 9, 10, 10, 11, 12, 13, 14 (list; graph; listen)
OFFSET

1,4

COMMENT

The shape of each row tends to a limit curve when scaled to a fixed size. It is the same limit curve as this continuous version: start with f_0=x over [0,1]; then repeatedly reverse (1-x), integrate from zero (x-x^2/2), scale to 1 (2x-x^2), and invert (1-sqrt(1-x)). For the limit curve we have f'(0) = F(1) = lim A011784(n+2)/(A011784(n+1)*A011784(n)) ~ 0.27887706 (obtained numerically) - Martin Fuller (martin_n_fuller(AT)btinternet.com), Aug 07 2006

FORMULA

n-th row sum = A011784(n+2); e.g. 5-th row is {1, 1, 1, 2, 2, 3, 4} and the sum of elements is 1+1+1+2+2+3+4=14=A011784(7) - Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 06 2003

EXAMPLE

{1,1}, {1,2}, {1,1,2}, {1,1,2,3}, {1,1,1,2,2,3,4}, {1,1,1,1,2,2,2,3,3,4,4,5,6,7}

CROSSREFS

Cf. A011784.

Adjacent sequences: A012254 A012255 A012256 this_sequence A012258 A012259 A012260

Sequence in context: A134024 A029316 A104368 this_sequence A101022 A051064 A078770

KEYWORD

nonn,tabf,nice

AUTHOR

Lionel Levine (levine(AT)ultranet.com)

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Last modified October 7 14:39 EDT 2008. Contains 144666 sequences.


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