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A194722 Number of n-ary words beginning with the first character of the alphabet, that can be built by inserting ten doublets into the initially empty word. 2
0, 1, 92378, 19319845, 560198962, 6507351113, 44731364266, 218878998733, 844131474530, 2730108129937, 7711583225338, 19564269083381, 45486599105938, 98378219490265, 200201768681162, 386776488742813, 714420272913346, 1268930908616993, 2177477525153050 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1000

FORMULA

G.f.: x * (1 +92368*x +18396110*x^2 +371157402*x^3 +1763669368*x^4 +2567824154*x^5 +1206169122*x^6 +163325950*x^7 +4293143*x^8 +4862*x^9) / (x-1)^10.

a(0) = 0, a(n) = 1 +(18 +(152 +(798 +(2907 +(7752 +(15504 +(23256 +(25194 +16796*(n-1)) *(n-1)) *(n-1)) *(n-1)) *(n-1)) *(n-1)) *(n-1)) * (n-1)) * (n-1) for n>0.

EXAMPLE

a(1) = 1: a^20 (with 1-ary alphabet {a}).

MAPLE

a:= n-> `if`(n=0, 0, (x-> 1+(18+(152+(798+(2907+(7752+(15504+(23256+

                     (25194+16796*x)*x)*x)*x)*x)*x)*x)*x)*x)(n-1)):

seq(a(n), n=0..30);

CROSSREFS

Row n=10 of A183134.

Sequence in context: A116122 A116134 A318631 * A140932 A208623 A294857

Adjacent sequences:  A194719 A194720 A194721 * A194723 A194724 A194725

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Sep 02 2011

STATUS

approved

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Last modified December 7 17:03 EST 2021. Contains 349581 sequences. (Running on oeis4.)