OFFSET
1,1
COMMENTS
Also, numbers k such that k^2 == 2 (mod 73).
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (1,1,-1).
FORMULA
a(n) = a(n-1) + a(n-2) - a(n-3) with a(1)=32, a(2)=41, a(3)=105.
a(n) = (73 + 55*(-1)^(n-1) + 146*(n-1))/4.
G.f.: x*(32 + 9*x + 32*x^2)/((1+x)*(x-1)^2). - R. J. Mathar, Jul 18 2009
MATHEMATICA
LinearRecurrence[{1, 1, -1}, {32, 41, 105}, 60] (* Harvey P. Dale, Aug 09 2016 *)
PROG
(Magma) I:=[32, 41, 105]; [n le 3 select I[n] else Self(n-1)+Self(n-2)-Self(n-3): n in [1..60]]; // Vincenzo Librandi, Mar 02 2012
(PARI) for(n=1, 50, print1((73+55*(-1)^(n-1)+146*(n-1))/4", ")); \\ Vincenzo Librandi, Mar 02 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jun 30 2009
EXTENSIONS
Sign of k in the definition clarified by R. J. Mathar, Jul 18 2009
New name from Charles R Greathouse IV, Jan 11 2012
STATUS
approved