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.
%I A102544 #14 Feb 21 2025 14:50:25 %S A102544 16,20,43,50,61,62,64,83,85,100,101,103,109,113,124,131,134,136,137, %T A102544 139,142,145,158,160,164,172,181,197,202,205,206,251,256,262,268,272, %U A102544 278,289,295,298,307,310,314,316,326,347,349,359,361,362,368,373,400,419,428,431,433,437,445 %N A102544 Numbers k such that k777777 is prime. %H A102544 Daniel Starodubtsev, <a href="/A102544/b102544.txt">Table of n, a(n) for n = 1..10000</a> %e A102544 If k=16, then k777777 = 16777777 (prime). %e A102544 If k=85, then k777777 = 85777777 (prime). %e A102544 If k=124, then k777777 = 124777777 (prime). %o A102544 (Magma) [ n: n in [1..700] | IsPrime(Seqint([7,7,7,7,7,7] cat Intseq(n))) ]; // _Vincenzo Librandi_, Feb 04 2011 %K A102544 base,nonn %O A102544 1,1 %A A102544 _Parthasarathy Nambi_, Feb 24 2005 %E A102544 More terms from _Vincenzo Librandi_, Feb 04 2011