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.

A174454 The smaller member p of a twin prime pair such that 5*p+6 is a square of a prime number.

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%I A174454 #11 Dec 24 2019 08:29:34
%S A174454 71,191,6551,35447,79631,103391,207671,254927,264959,421079,479879,
%T A174454 592367,700127,745751,949607,986567,1013399,1271087,1456919,1478591,
%U A174454 1859279,2085287,2272727,2841071,5204039,5472671,6003887,6202751
%N A174454 The smaller member p of a twin prime pair such that 5*p+6 is a square of a prime number.
%C A174454 Subsequence of A174370 and of A001359.
%H A174454 Amiram Eldar, <a href="/A174454/b174454.txt">Table of n, a(n) for n = 1..10000</a>
%e A174454 (71,73) are twin primes, and 5 * 71 + 6 = 19^2 is a square of a prime, which adds 71 to the sequence.
%e A174454 (9767,9769) are twin primes, 5 * 9767 + 6 = 221^2, but 221 = 13 * 17 is not prime, so 9767 is not in the sequence.
%t A174454 Select[Transpose[Select[Partition[Prime[Range[430000]],2,1], Last[#]- First[#] ==2&]][[1]],PrimeQ[Sqrt[5#+6]]&]  (* _Harvey P. Dale_, Apr 22 2011 *)
%t A174454 Select[(Select[Range[5569], PrimeQ]^2 - 6)/5, And @@ PrimeQ[# + {0, 2}] &] (* _Amiram Eldar_, Dec 24 2019 *)
%Y A174454 Cf. A001359, A174370.
%K A174454 nonn
%O A174454 1,1
%A A174454 Ulrich Krug (leuchtfeuer37(AT)gmx.de), Mar 20 2010
%E A174454 Definition simplified, cross-references to unrelated sequences removed - _R. J. Mathar_, Nov 01 2010