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A375497
Numbers k such that 16*k^4 - 1 is squarefree.
0
1, 2, 3, 6, 7, 8, 10, 11, 15, 17, 18, 20, 21, 26, 27, 28, 29, 30, 33, 36, 39, 42, 43, 44, 45, 46, 47, 48, 51, 52, 53, 54, 55, 56, 57, 64, 65, 69, 70, 71, 72, 75, 78, 79, 80, 81, 82, 83, 89, 90, 92, 93, 96, 97, 98, 99, 100, 101, 102, 105, 106, 107, 108, 110, 111, 114, 115, 117, 118, 119, 120
OFFSET
1,2
MAPLE
select(k -> numtheory:-issqrfree(16*k^4-1), [$1..200]); # Robert Israel, Aug 18 2024
MATHEMATICA
Select[Range[120], SquareFreeQ[16 * #^4 - 1] &] (* Amiram Eldar, Aug 18 2024 *)
PROG
(Magma) [k: k in [1..120] | IsSquarefree(16*k^4-1)];
(PARI) isok(k) = issquarefree(16*k^4 - 1); \\ Michel Marcus, Aug 18 2024
CROSSREFS
Sequence in context: A332021 A047560 A032899 * A193528 A232681 A296350
KEYWORD
nonn
AUTHOR
STATUS
approved