A097381 - OEIS

%I #9 Feb 01 2024 08:30:20

%S 1,2,6,10,12,14,18,24,26,48,54,60,66,74,84,94,96,98,110,120,130,132,

%T 134,146,162,168,170,192,204,206,210,230,234,240,264,300,314,326,336,

%U 372,384,386,406,408,430,466,470,474,480,486,490,528,570,588,600,634,646

%N Numbers m such that 1+SquareFreeKernel(m)*CubeFreeKernel(m) is prime.

%H Amiram Eldar, <a href="/A097381/b097381.txt">Table of n, a(n) for n = 1..10000</a>

%F A097378(a(n)) is prime.

%t 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 *)

%o (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

%Y Cf. A007947, A007948, A097379, A097380.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Aug 11 2004