cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A361696 Semiprimes of the form k^2 + 5.

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%I A361696 #16 Aug 21 2025 08:29:48
%S A361696 6,9,14,21,69,86,201,329,446,489,581,681,734,789,905,1094,1769,1941,
%T A361696 2606,2921,3254,3369,3849,3974,4101,4629,4766,6729,7061,7401,8105,
%U A361696 8654,9609,9806,10409,10821,11669,12326,13929,17429,17961,19049,20741,23109,23721,24341,27561,30281,31334,32405
%N A361696 Semiprimes of the form k^2 + 5.
%H A361696 Paolo Xausa, <a href="/A361696/b361696.txt">Table of n, a(n) for n = 1..10000</a>
%F A361696 a(n) = A242333(n)^2 + 5.
%e A361696 69 is a term because 8^2 + 5 = 69 = 3*23.
%t A361696 Select[Range[200]^2 + 5, PrimeOmega[#] == 2 &] (* _Paolo Xausa_, Aug 21 2025 *)
%o A361696 (PARI) isok(k) = issquare(k-5) && (bigomega(k)==2); \\ _Michel Marcus_, Mar 27 2023
%Y A361696 Cf. A144255, A242333, A360739, A360740, A360741.
%Y A361696 Intersection of A117951 and A001358.
%K A361696 nonn,easy
%O A361696 1,1
%A A361696 _Elmo R. Oliveira_, Mar 20 2023