OFFSET
0,1
COMMENTS
Solutions to (7^x + 11^x) mod 17 = 13.
a(n-2), n>=2, gives the second column in triangle A238476 related to the Collatz problem. - Wolfdieter Lang, Mar 12 2014
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Tanya Khovanova, Recursive Sequences
Leo Tavares, Illustration: Bounded Star Crosses
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(n) = 16*n + 13.
a(n) = 32*n - a(n-1) + 10; a(0)=13. - Vincenzo Librandi, Oct 10 2011
From Stefano Spezia, Dec 27 2019: (Start)
O.g.f.: (13 + 3*x)/(1 - x)^2.
E.g.f.: exp(x)*(13 + 16*x).
(End)
MATHEMATICA
Range[13, 1000, 16] (* Vladimir Joseph Stephan Orlovsky, May 31 2011 *)
LinearRecurrence[{2, -1}, {13, 29}, 60] (* Harvey P. Dale, Jan 28 2023 *)
PROG
(PARI) \\ solutions to 7^x+11^x == 13 mod 17
anpbn(n) = { for(x=1, n, if((7^x+11^x-13)%17==0, print1(x" "))) }
(Magma) [[ n : n in [1..1000] | n mod 16 eq 13]]; // Vincenzo Librandi, Oct 10 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, May 10 2003
STATUS
approved