OFFSET
1,1
COMMENTS
First prime: a(19) = 3765432098765432101. Next prime: a(271) = 3*10^270 + 765432098*(10^(9*29)-1)*10^9/(10^9-1) + 765432129. - Bruno Berselli, Oct 15 2013
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (12,-21,10).
FORMULA
from Bruno Berselli, Oct 15 2013: (Start)
G.f.: x*(4 -10*x +5*x^2)/((1-10*x)*(1-x)^2).
a(n) = 12*a(n-1) -21*a(n-2) +10*a(n-3). (End)
E.g.f.: (1/162)*(-81 + 2*(10 + 9*x)*exp(x) + 61*exp(10*x)). - G. C. Greubel, Jun 04 2021
MATHEMATICA
Table[(1/162)*(61*10^n +18*n +20), {n, 20}] (* Bruno Berselli, Oct 15 2013 *)
PROG
(PARI) a(n) = (1/162)*(61*10^n + 18*n + 20); \\ Michel Marcus, Oct 15 2013
(Magma) [(1/162)*(61*10^n+18*n+20): n in [1..20]]; // Bruno Berselli, Oct 15 2013
(Sage) [1/162)*(61*10^n +18*n +20) for n in (1..20)] # G. C. Greubel, Jun 04 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Zak Seidov, Jan 29 2009
STATUS
approved