OFFSET
0,2
COMMENTS
Take 31 numbers consisting of 29 ones together with any two successive terms from this sequence. This set has the property that the sum of their squares is 31 times their product. (Guy)
Positive values of x (or y) satisfying x^2 - 31xy + y^2 + 29 = 0. - Colin Barker, Feb 24 2014
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Tanya Khovanova, Recursive Sequences
Index entries for linear recurrences with constant coefficients, signature (31,-1).
FORMULA
G.f.: (1-x)/(1-31*x+x^2). [Philippe Deléham, Nov 18 2008]
MATHEMATICA
CoefficientList[Series[(1 - x)/(1 - 31 x + x^2), {x, 0, 40}], x] (* Vincenzo Librandi, Feb 26 2014 *)
PROG
(PARI) Vec((1-x)/(1-31*x+x^2) + O(x^100)) \\ Colin Barker, Feb 24 2014
(Magma) I:=[1, 30]; [n le 2 select I[n] else 31*Self(n-1)-Self(n-2): n in [1..20]]; // Vincenzo Librandi, Feb 26 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, following a suggestion from R. K. Guy, Oct 26 2005
STATUS
approved