OFFSET
1,1
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
Cino Hilliard, Simultaneous Equations and Curve Fitting. [broken link]
Index entries for linear recurrences with constant coefficients, signature (1,1,-1).
FORMULA
Numbers of the form 11*n+1 with n odd or 11*n-2 with n even.
From Colin Barker, Jun 09 2016: (Start)
a(n) = (-1-3*(-1)^n+22*n)/2.
a(n) = a(n-1)+a(n-2)-a(n-3) for n>3.
G.f.: 2*x*(6+4*x+x^2) / ((1-x)^2*(1+x)).
(End)
MATHEMATICA
Table[If[OddQ[n], 11n + 1, 11 n - 2], {n, 60}] (* Vincenzo Librandi, Jun 09 2016 *)
PROG
(PARI) anpbn(n) = { for(x=1, n, if((13^x+17^x-19)%23==0, print1(x", "))) }
(Magma) [IsOdd(n) select 11*n+1 else 11*n-2: n in [1..60]]; // Vincenzo Librandi, Jun 09 2016
(PARI) Vec(2*x*(6+4*x+x^2)/((1-x)^2*(1+x)) + O(x^100)) \\ Colin Barker, Jun 09 2016
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, May 10 2003
STATUS
approved