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A060851 (2n-1) * 3^(2n-1). 2
3, 81, 1215, 15309, 177147, 1948617, 20726199, 215233605, 2195382771, 22082967873, 219667417263, 2165293113021, 21182215236075, 205891132094649, 1990280943581607, 19147875284802357, 183448998696332259, 1751104078464989745, 16660504517966902431 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

S. R. Finch, Mathematical Constants, Cambridge, 2003, pp. 28-40.

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,200

Xavier Gourdon and Pascal Sebah, Riemann's zeta function

Pablo A. Panzone, Formulas for the Euler-Mascheroni constant, Rev. Un. Mat. Argentina, Vol 50, No. 1 (2009), pp. 161-164.

Simon Plouffe, Other interesting computations

Index to sequences with linear recurrences with constant coefficients, signature (18,-81)

FORMULA

G.f. 3*x*(1+9*x) / (9*x-1)^2 . a(n+1)=3*A155988(n). - R. J. Mathar, May 07 2013

EXAMPLE

log(2) = sum( 2 / a(n)) for n = 1..infinity.

C0 = sum( 2 / a(n) - zeta(2n+1) / [ ( 2^(2n)) * (2n+1) ] ).

C0 = sum( [ (4n+2) / a(n) - zeta(2n+1) / (2^(2n)) ] / (2n+1)).

7/4= sum( [ (4n+2) / a(n) - zeta(2n+1) / (2^(2n)) ] ).

7/8= sum( [ (2n+1) / a(n) - zeta(2n+1) / (2^(2n+1)) ] ).

MAPLE

A060851:=n->(2*n-1)*3^(2*n-1); seq(A060851(n), n=1..20); # Wesley Ivan Hurt, Dec 02 2013

MATHEMATICA

Table[(2*n - 1)*3^(2*n - 1), {n, 20}] (* Wesley Ivan Hurt, Dec 02 2013 *)

PROG

(PARI) { for (n=1, 200, write("b060851.txt", n, " ", (2*n - 1)*(3^(2*n - 1))); ) } [Harry J. Smith, Jul 13 2009]

(MAGMA) [ (2*n-1) * (3^(2*n-1)): n in [1..100]]; // Vincenzo Librandi, Apr 20 2011

CROSSREFS

For log(2) see A002162, for Euler's constant C0 see A001620.

Sequence in context: A123656 A229842 A223187 * A116179 A013732 A209587

Adjacent sequences:  A060848 A060849 A060850 * A060852 A060853 A060854

KEYWORD

nonn,easy

AUTHOR

Frank Ellermann, May 03 2001

EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), May 07 2001

STATUS

approved

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Last modified December 22 19:34 EST 2014. Contains 252365 sequences.