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 A181460 #22 Dec 20 2024 18:16:53 %S A181460 46,48,93,95,142,187,189,281,375,377,424,469,610,657,659,704,751,753, %T A181460 892,988,1033,1035,1082,1174,1223,1270,1364,1409,1597,1599,1691,1693, %U A181460 1926,1973,1975,2022,2069,2161,2255,2351,2443,2584,2727,2913,2915,3009 %N A181460 Numbers k such that 47 is the largest prime factor of k^2-1. %C A181460 Numbers k such that A076605(k) = 47. %C A181460 Sequence is finite, for proof see A175607. %C A181460 Search for terms can be restricted to the range from 2 to A175607(15) = 2218993446251; primepi(47) = 15. %H A181460 Artur Jasinski, <a href="/A181460/b181460.txt">Table of n, a(n) for n = 1..433</a> %t A181460 Select[Range[300000], FactorInteger[#^2-1][[-1, 1]]==47&] %o A181460 (Magma) [ n: n in [2..300000] | m eq 47 where m is D[#D] where D is PrimeDivisors(n^2-1) ]; // _Klaus Brockhaus_, Feb 19 2011 %o A181460 (PARI) is(n)=n=n^2-1; forprime(p=2, 43, n/=p^valuation(n, p)); n>1 && 47^valuation(n, 47)==n \\ _Charles R Greathouse IV_, Jul 01 2013 %Y A181460 Cf. A076605, A175607, A181447-A181459, A181461-A181470, A181568. %K A181460 fini,full,nonn %O A181460 1,1 %A A181460 _Artur Jasinski_, Oct 21 2010