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A074600 a(n) = 2^n + 5^n. 56
2, 7, 29, 133, 641, 3157, 15689, 78253, 390881, 1953637, 9766649, 48830173, 244144721, 1220711317, 6103532009, 30517610893, 152587956161, 762939584197, 3814697527769, 19073486852413, 95367432689201, 476837160300277 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
COMMENTS
Digital root of a(n) is A010697(n). - Peter M. Chema, Oct 24 2016
REFERENCES
Miller, Steven J., ed. Benford's Law: Theory and Applications. Princeton University Press, 2015. See page 14.
LINKS
D. Suprijanto, I. W. Suwarno, Observation on Sums of Powers of Integers Divisible by 3k-1, Applied Mathematical Sciences, Vol. 8, 2014, no. 45, pp. 2211-2217.
FORMULA
a(n) = 5*a(n-1)-3*2^(n-1) = 7*a(n-1)- 10*a(n-2). [Corrected by Zak Seidov, Oct 24 2009]
G.f.: 1/(1-2*x)+1/(1-5*x). E.g.f.: e^(2*x)+e^(5*x). - Mohammad K. Azarian, Jan 02 2009
MATHEMATICA
Table[2^n + 5^n, {n, 0, 25}]
LinearRecurrence[{7, -10}, {2, 7}, 30] (* Harvey P. Dale, May 09 2019 *)
PROG
(Magma) [2^n + 5^n: n in [0..35]]; // Vincenzo Librandi, Apr 30 2011
(PARI) a(n)=2^n+5^n \\ Charles R Greathouse IV, Sep 24 2015
CROSSREFS
Sequence in context: A366084 A368935 A110576 * A064641 A183608 A307389
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Aug 25 2002
STATUS
approved

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Last modified March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)