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A170745 G.f.: (1+x)/(1-25*x). 50
1, 26, 650, 16250, 406250, 10156250, 253906250, 6347656250, 158691406250, 3967285156250, 99182128906250, 2479553222656250, 61988830566406250, 1549720764160156250, 38743019104003906250, 968575477600097656250, 24214386940002441406250, 605359673500061035156250 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Kenny Lau, Table of n, a(n) for n = 0..715

Index entries for linear recurrences with constant coefficients, signature (25).

FORMULA

a(n) = Sum_{k=0..n} A097805(n,k)*(-1)^(n-k)*26^k. - Philippe Deléham, Dec 04 2009

a(0) = 1; for n>0, a(n) = 26*25^(n-1). - Vincenzo Librandi, Dec 05 2009

MATHEMATICA

CoefficientList[Series[(1+x)/(1-25*x), {x, 0, 20}], x] (* or *) Join[ {1}, NestList[25#&, 26, 20]] (* Harvey P. Dale, Aug 08 2019 *)

PROG

(Python) for i in range(1001):print(i, 26*25**(i-1) if i>0 else 1) # Kenny Lau, Aug 03 2017

CROSSREFS

Sequence in context: A170611 A170659 A170707 * A218728 A209963 A158542

Adjacent sequences:  A170742 A170743 A170744 * A170746 A170747 A170748

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 04 2009

STATUS

approved

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Last modified September 20 20:12 EDT 2019. Contains 327247 sequences. (Running on oeis4.)