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A271263
Septic artiads (A270800) congruent to 1 mod 98 and for which 2 is a 7th power residue.
1
874651, 941879, 1074277, 1080451, 1396697, 2024387, 2546237, 2807603, 3267419, 3324847, 3436273, 3465673, 3851009, 4150301, 4219979, 4367567, 4651963, 4762507, 5173813, 5308759, 5398919, 5474477, 5552191, 5710363, 6248579, 6391267, 6575507, 6627251, 6791107
OFFSET
1,1
LINKS
E. Lehmer, Artiads characterized, J. Math. Anal. Appl. 15 1966 118-131. See p. 128, Theorem 7.
E. Lehmer, Artiads characterized, J. Math. Anal. Appl. 15 1966 118-131 [annotated and corrected scanned copy]
PROG
(Sage)
def isa(n) :
if not (n % 98 == 1 and is_prime(n)) : return False
R.<t> = PolynomialRing(GF(n))
return 2.powermod((n-1)//7, n) == 1 and all(r[0]^((n-1)//7) == 1 for r in (t^3 + t^2 - 2*t - 1).roots())
CROSSREFS
Sequence in context: A306868 A223886 A204509 * A253523 A254421 A254428
KEYWORD
nonn
AUTHOR
Eric M. Schmidt, Apr 03 2016
STATUS
approved