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A214274
Number of compositions of n where the difference between largest and smallest parts equals 5 and adjacent parts are unequal.
2
0, 2, 1, 8, 12, 23, 56, 95, 186, 349, 649, 1181, 2168, 3932, 7045, 12741, 22716, 40528, 72086, 127802, 226191, 399378, 704011, 1238513, 2176306, 3817950, 6689530, 11707266, 20465195, 35738757, 62350777, 108682236, 189279785, 329390352, 572788101, 995343179
OFFSET
6,2
LINKS
Alois P. Heinz and Vaclav Kotesovec, Table of n, a(n) for n = 6..2000 (first 250 terms from Alois P. Heinz)
FORMULA
a(n) ~ c * d^n, where d = 1.70794647064333012330..., c = 0.5176707727128993957... . - Vaclav Kotesovec, Sep 01 2014
EXAMPLE
a(7) = 2: [6,1], [1,6].
a(8) = 1: [1,6,1].
a(9) = 8: [7,2], [6,2,1], [6,1,2], [2,7], [2,6,1], [2,1,6], [1,6,2], [1,2,6].
a(10) = 12: [6,3,1], [6,1,3], [6,1,2,1], [3,6,1], [3,1,6], [2,1,6,1], [1,6,3], [1,6,2,1], [1,6,1,2], [1,3,6], [1,2,6,1], [1,2,1,6].
CROSSREFS
Column k=5 of A214269.
Sequence in context: A137370 A214272 A214273 * A214275 A214276 A214277
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jul 09 2012
STATUS
approved