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A097381
Numbers m such that 1+SquareFreeKernel(m)*CubeFreeKernel(m) is prime.
4
1, 2, 6, 10, 12, 14, 18, 24, 26, 48, 54, 60, 66, 74, 84, 94, 96, 98, 110, 120, 130, 132, 134, 146, 162, 168, 170, 192, 204, 206, 210, 230, 234, 240, 264, 300, 314, 326, 336, 372, 384, 386, 406, 408, 430, 466, 470, 474, 480, 486, 490, 528, 570, 588, 600, 634, 646
OFFSET
1,2
LINKS
FORMULA
A097378(a(n)) is prime.
MATHEMATICA
f[p_, e_] := p^(1 + Min[e, 2]); s[1] = 2; s[n_] := 1 + Times @@ f @@@ FactorInteger[n]; Select[Range[650], PrimeQ[s[#]] &] (* Amiram Eldar, Feb 01 2024 *)
PROG
(PARI) is(n) = {my(f = factor(n)); isprime(1 + prod(i = 1, #f~, f[i, 1]^(1 + min(f[i, 2], 2)))); } \\ Amiram Eldar, Feb 01 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Aug 11 2004
STATUS
approved