A084083 - OEIS

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A084083

Length of lists created by n substitutions k -> Range[k+1,-Abs[k],-2] starting with {1}.

0

1, 2, 4, 9, 19, 44, 96, 227, 507, 1218, 2768, 6732, 15504, 38076, 88616, 219351, 514855, 1282710, 3031860, 7594665

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..19.

EXAMPLE

{1}, {2,0}, {3,1,-1,1}, {4,2,0,-2,2,0,0,2,0} have lengths 1, 2, 4, 9.

MATHEMATICA

Length/@Flatten/@NestList[ # /. k_Integer:>Range[k+1, -Abs[k], -2]&, {1}, 16]

CROSSREFS

Sequence in context: A117160 A339156 A247623 * A036611 A316473 A316501

Adjacent sequences: A084080 A084081 A084082 * A084084 A084085 A084086

KEYWORD

nonn

AUTHOR

Wouter Meeussen, May 11 2003

EXTENSIONS

a(17)-a(19) from Robert G. Wilson v, Aug 17 2009

STATUS

approved