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A034491 7^n + 1. 46
2, 8, 50, 344, 2402, 16808, 117650, 823544, 5764802, 40353608, 282475250, 1977326744, 13841287202, 96889010408, 678223072850, 4747561509944, 33232930569602, 232630513987208, 1628413597910450, 11398895185373144 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Numbers n for which the expression 7^n/(n-1) is an integer. - Paolo P. Lava, May 29 2006

LINKS

T. D. Noe, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (8,-7).

FORMULA

a(n) = 7a(n-1) - 6 = 8a(n-1) - 7a(n-2).

G.f.: 1/(1-x)+1/(1-7*x). E.g.f.: e^x+e^(7*x). - Mohammad K. Azarian, Jan 02 2009

MATHEMATICA

Table[7^n + 1, {n, 0, 20}]

PROG

(Sage) [sigma(7, n)for n in xrange(0, 20)] # - Zerinvary Lajos, Jun 04 2009

(PARI) a(n)=7^n+1 \\ Charles R Greathouse IV, Sep 24 2015

CROSSREFS

Cf. A000051, A034472, A052539, A034474, A062394, A062395, A062396, A062397, A007689, A063376, A063481, A074600-A074624, A034524, A178248, A228081.

Sequence in context: A227264 A114619 A027047 * A231352 A186182 A274273

Adjacent sequences:  A034488 A034489 A034490 * A034492 A034493 A034494

KEYWORD

easy,nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified August 21 19:52 EDT 2017. Contains 290906 sequences.