%I #14 Jul 03 2022 09:24:37

%S 1,13,37,61,73,97,109,157,169,181,193,229,241,277,313,337,349,373,397,

%T 409,421,433,457,481,541,577,601,613,661,673,709,733,757,769,793,829,

%U 853,877,937,949,997,1009,1021,1033,1069,1093,1117,1129,1153,1201,1213

%N Positive integers whose prime factors are congruent to 1 (mod 12).

%C All the prime factors of each term in this sequence are terms of A068228.

%t Select[Range[10000], Count[Mod[First /@ FactorInteger[#], 12], 1] == Length[FactorInteger[#]] &]

%o (PARI) isok(m) = my(f=factor(m)); for (k=1, #f~, if ((f[k,1] % 12) != 1, return(0))); return (1); \\ _Michel Marcus_, Jun 02 2022

%Y Cf. A068228.

%K nonn

%O 1,2

%A _Steven Lu_, Jun 01 2022