A128162 a(n) = 3^n modulo Fibonacci(n).

0, 0, 1, 0, 3, 1, 3, 9, 31, 34, 37, 81, 137, 347, 487, 690, 355, 1369, 2001, 1926, 5331, 1369, 4823, 8289, 74043, 77951, 188571, 284781, 490766, 166409, 1333373, 1803615, 1516839, 914943, 3619092, 3987873, 17604245, 8506938, 57277423, 24741861

Offset

1,5

Comments

Numbers k such that a(k) is prime are listed in A128163. Corresponding primes in {a(n)} are {3, 3, 31, 37, 137, 347, 487, 77951, 166409, 13506083561, ...}.

Links

Robert Israel, Table of n, a(n) for n = 1..4783

Maple

f:= n -> 3 &^ n mod combinat:-fibonacci(n):
map(f, [$1..100]); # Robert Israel, Jul 10 2020

Mathematica

Table[PowerMod[3, n, Fibonacci[n]], {n, 1, 100}]

Prog

(Sage) [power_mod(3, n, fibonacci(n))for n in range(1, 41)] # - Zerinvary Lajos, Nov 28 2009
(PARI) a(n)=3^n%fibonacci(n) \\ Charles R Greathouse IV, Jun 19 2017

Crossrefs

Cf. A128163, A128161, A057862 (2^n modulo Fibonacci(n)).

Sequence in context: A146436 A058842 A155734 * A257253 A067329 A170860

Adjacent sequences: A128159 A128160 A128161 * A128163 A128164 A128165

Keyword

nonn

Author

Alexander Adamchuk, Feb 19 2007

Status

approved