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 A181455 #23 Dec 20 2024 18:16:13 %S A181455 28,57,59,86,115,144,146,175,231,233,289,349,376,407,436,463,494,521, %T A181455 579,639,666,755,811,987,1101,1103,1217,1275,1451,1565,1567,1681,2029, %U A181455 2089,2551,2872,2899,3191,3249,3365,4001,4003,4351,4409,4523,4929,5279 %N A181455 Numbers k such that 29 is the largest prime factor of k^2 - 1. %C A181455 Numbers k such that A076605(k) = 29. %C A181455 Sequence is finite. For proof see A175607. %C A181455 Search for terms can be restricted to the range from 2 to A175607(10) = 354365441; primepi(29) = 10. %H A181455 Artur Jasinski, <a href="/A181455/b181455.txt">Table of n, a(n) for n = 1..126</a> %t A181455 Select[Range[5600],FactorInteger[#^2-1][[-1,1]]==29&] (* _Harvey P. Dale_, Feb 16 2011 *) %o A181455 (Magma) [ n: n in [2..6000] | m eq 29 where m is D[#D] where D is PrimeDivisors(n^2-1) ]; // _Klaus Brockhaus_, Feb 17 2011 %o A181455 (PARI) is(n)=n=n^2-1; forprime(p=2, 23, n/=p^valuation(n, p)); n>1 && 29^valuation(n, 29)==n \\ _Charles R Greathouse IV_, Jul 01 2013 %Y A181455 Cf. A076605, A175607, A181447-A181470, A181568. %K A181455 fini,full,nonn %O A181455 1,1 %A A181455 _Artur Jasinski_, Oct 21 2010