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A367104 First of 5 consecutive semiprimes congruent to 1,2,3,4,5 (mod 6). 1

%I #9 Nov 04 2023 23:18:55

%S 25,133,187,4873,5713,8005,11293,11707,13645,19657,33853,37033,48217,

%T 58117,74701,81541,84907,106177,107257,113977,114559,117313,130837,

%U 154273,158845,162397,168997,174073,181057,202927,208477,229513,233845,236059,246601,266173,274717,280813,283333,304585

%N First of 5 consecutive semiprimes congruent to 1,2,3,4,5 (mod 6).

%H Robert Israel, <a href="/A367104/b367104.txt">Table of n, a(n) for n = 1..838</a>

%H David A. Corneth, <a href="/A367104/a367104.gp.txt">PARI program</a>

%e a(3) = 187 is a term because 187,194,201,202,203 are consecutive semiprimes congruent to 1, 2, 3, 4, 5 (mod 6) respectively.

%p sp:= select(t -> numtheory:-bigomega(t)=2, [$4..10^6]):

%p sp6:= sp mod 6:

%p sp[select(i -> sp6[i..i+4] = [$1..5], [$1..nops(sp)-5])];

%o (PARI) \\ See PARI program

%Y Cf. A001358.

%K nonn

%O 1,1

%A _Zak Seidov_ and _Robert Israel_, Nov 04 2023

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Last modified August 29 13:45 EDT 2024. Contains 375517 sequences. (Running on oeis4.)