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A093372
Composite k such that Fibonacci(k) == Legendre(k,5) == 1 (mod k).
4
4181, 5474, 6479, 6721, 13201, 15251, 27071, 34561, 44099, 47519, 51841, 54839, 64079, 64681, 65471, 67861, 68251, 72831, 78089, 90061, 96049, 97921, 109871, 118441, 139359, 146611, 157079, 163081, 168299, 186961, 196559, 197209, 219781
OFFSET
1,1
LINKS
MATHEMATICA
Select[ Range[ 2, 100000 ], ! PrimeQ[ # ] && Mod[ Fibonacci[ # ] - JacobiSymbol[ #, 5 ], # ] == 0 && JacobiSymbol[ #, 5 ] == 1 & ]
PROG
(Python)
from itertools import islice
from sympy import nextprime
from sympy.functions.combinatorial.numbers import legendre_symbol
from oeis_sequences.OEISsequences import fibonacci_mod
def A093372_gen(): # generator of terms
p, q = 4, 5
while True:
for m in range(p, q):
if fibonacci_mod(m, m) == 1 and legendre_symbol(m, 5) == 1:
yield m
p, q = q+1, nextprime(q)
A093372_list = list(islice(A093372_gen(), 30)) # Chai Wah Wu, Jul 13 2026
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 29 2004
EXTENSIONS
More terms from Eric Rowland, Apr 29 2004
More terms from Ryan Propper, Jul 21 2006
STATUS
approved