OFFSET
1,1
REFERENCES
E. Grosswald, Topics From The Theory of Numbers, 1966, pp. 62-63.
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,0,0,1,-1).
FORMULA
G.f.: x*(2 + 4*x + x^2 + 4*x^3 + 2*x^4)/(1 - x - x^4 + x^5). - Philippe Deléham, Dec 01 2016
EXAMPLE
2^11 - 7 = 2041 = 11*157. Thus 2 is in the sequence.
MATHEMATICA
LinearRecurrence[{1, 0, 0, 1, -1}, {2, 6, 7, 11, 15}, 60] (* Ray Chandler, Aug 25 2015 *)
PROG
(PARI) conxkmap(a, p, n) = { for(x=1, n, for(j=1, n, y=x^j-a; if(y%p==0, print1(x", "); break) ) ) }
(Magma) I:=[2, 6, 7, 11, 15]; [n le 5 select I[n] else Self(n-1)+Self(n-4)-Self(n-5): n in [1..70]]; // Vincenzo Librandi, Dec 02 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Cino Hilliard, Nov 03 2003
STATUS
approved