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A168431 General number of transpositions of n objects with repetitions. 0
1, 2, 9, 46, 245, 1601 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..6.

FORMULA

Apparently a(n)=A005651(n)-1, n>1. [From R. J. Mathar, Nov 26 2009]

EXAMPLE

a(1)=1!/1!=1 because A035294(1)=1; a(2)=2!/(1!*1!)=2 because A035294(2)=1; a(3)=3!/(1!*1!*1!)+3!/(2!*1!)=9 because A035294(3)=2; a(4)=4!/(1!*1!*1!*1!)+4!/(2!*1!*1!)+4!/(2!*2!)+4!/(3!*1!)=46 because A035294(4)=4; a(5)=5!/(1!*1!*1!*1!*1!)+5!/(2!*1!*1!*1!)+5!/(2!*2!*1!)+5!/(3!*1!*1!)+5!/(3!*2!)+5!/(4!*1!)=245 because A035294(5)=6; a(6)=6!/(1!*1!*1!*1!*1!*1!)+6!/(2!*1!*1!*1!*1!)+6!/(2!*2!*1!*1!)+6!/(2!*2!*2!)+6!/(3!*1!*1!*1!)+6!/(3!*2!*1!)+6!/(3!*3!)+6!/(4!*1!*1!)+6!/(4!*2!)+6!/(5!*1!)=1601 because A035294(6)=10.

CROSSREFS

Cf. A035294.

Cf. A036038. [From R. J. Mathar, Nov 26 2009]

Sequence in context: A251178 A162725 A268171 * A036726 A219197 A340942

Adjacent sequences:  A168428 A168429 A168430 * A168432 A168433 A168434

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Nov 25 2009

STATUS

approved

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Last modified July 28 08:21 EDT 2021. Contains 346321 sequences. (Running on oeis4.)