A363172 Primitive terms of A363171: terms of A363171 with no proper divisor in A363171.

6, 10, 14, 44, 52, 105, 136, 152, 184, 232, 248, 286, 374, 418, 442, 495, 506, 592, 656, 688, 752, 848, 944, 976, 1292, 1564, 1748, 1755, 1972, 2108, 2144, 2145, 2204, 2272, 2336, 2356, 2516, 2528, 2656, 2668, 2788, 2805, 2812, 2848, 2852, 2924, 2925, 3104, 3116

Offset: 1

Author

Amiram Eldar, May 19 2023

Keywords

• nonn

Comments

If k is a term then m*k is a term of A363171 for all m >= 1.

The least odd term is a(6) = 105, and the least term that is coprime to 6 is a(34832) = 37182145.

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A363171.

Programs

Mathematica

q[n_] := DivisorSigma[-1, n * Times @@ FactorInteger[n][[;; , 1]]] > 2; primQ[n_] := q[n] && AllTrue[Divisors[n], # == n || ! q[#] &]; Select[Range[3200], primQ]

PARI

A064549(n) = { my(f=factor(n)); prod(i=1, #f~, f[i, 1]^(f[i, 2]+1)); };
isA363171(n) = sigma(A064549(n), -1) > 2;
is(n) = { if(!isA363171(n), return(0)); fordiv(n, d, if(d < n && isA363171(d), return(0))); return(1) };