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.

A102764 Numbers k such that k7777777 is prime.

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%I A102764 #11 Sep 08 2022 08:45:16
%S A102764 13,19,30,34,43,52,54,57,58,64,69,78,82,94,96,124,145,148,157,165,177,
%T A102764 178,187,192,195,201,202,243,246,250,256,264,277,291,303,307,313,319,
%U A102764 324,325,340,342,352,355,382,393,397,402,409,429,430,432,444,456,468,474,486,493,499,517
%N A102764 Numbers k such that k7777777 is prime.
%H A102764 Harvey P. Dale, <a href="/A102764/b102764.txt">Table of n, a(n) for n = 1..1000</a>
%e A102764 If k=13, then k7777777 = 137777777 (prime).
%e A102764 If k=57, then k7777777 = 577777777 (prime).
%e A102764 If k=96, then k7777777 = 967777777 (prime).
%t A102764 Select[Range[600],PrimeQ[#*10^7+7777777]&] (* _Harvey P. Dale_, Jan 02 2015 *)
%o A102764 (Magma) [ n: n in [1..700] | IsPrime(Seqint([7,7,7,7,7,7,7] cat Intseq(n))) ]; // _Vincenzo Librandi_, Feb 03 2011
%K A102764 base,nonn
%O A102764 1,1
%A A102764 _Parthasarathy Nambi_, Feb 25 2005