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Primes p such that b = 2*p + 1 is semiprime and c = 2*b + 1 is 3-almost prime.
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%I #8 Feb 22 2014 21:13:40

%S 43,503,631,827,971,1063,1153,1283,1373,1429,1433,1493,1523,1553,1619,

%T 1693,1877,2113,2239,2243,2297,2423,2477,2531,2609,2683,2851,2927,

%U 2999,3203,3221,3319,3463,3533,3557,3571,3583,3701

%N Primes p such that b = 2*p + 1 is semiprime and c = 2*b + 1 is 3-almost prime.

%C Subsequence of A234095 and A000040, e.g., a(1) = 43 = A234095(4) = A000040(14).

%e 2*43 + 1 = 87 = 2*29 = A001358(30), 2*87 + 1 = 175 = 5*5*7 = A014612(43).

%o (PARI) forprime(p=2,4000,if(bigomega(a=2*p+1)==2&&bigomega(b=2*a+1)==3,print(p",")))

%Y Cf. A000040, A001358, A014612, A234095.

%K nonn

%O 1,1

%A _Zak Seidov_, Feb 20 2014