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 A074773 #24 Feb 16 2025 08:32:47 %S A074773 3215031751,118670087467,307768373641,315962312077,354864744877, %T A074773 457453568161,528929554561,546348519181,602248359169,1362242655901, %U A074773 1871186716981,2152302898747,2273312197621,2366338900801,3343433905957,3461715915661,3474749660383,3477707481751,4341937413061,4777422165601,5537838510751 %N A074773 Strong pseudoprimes to bases 2, 3, 5 and 7. %H A074773 Charles R Greathouse IV, <a href="/A074773/b074773.txt">Table of n, a(n) for n = 1..10000</a> %H A074773 Washington Bomfim, <a href="/A074773/a074773.txt">Table with all 16757 terms up to 2^64</a> %H A074773 G. Jaeschke, <a href="http://dx.doi.org/10.1090/S0025-5718-1993-1192971-8">On strong pseudoprimes to several bases</a>, Mathematics of Computation, 61 (1993), 915-926. %H A074773 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MillersPrimalityTest.html">Miller's Primality Test</a> %H A074773 <a href="/index/Ps#pseudoprimes">Index entries for sequences related to pseudoprimes</a> %o A074773 (PARI) sprp(n,b)=my(s=valuation(n-1,2),d=Mod(b,n)^(n>>s)); if(d==1, return(1)); for(i=1,s-1, if(d==-1, return(1)); d=d^2;); d==-1 %o A074773 is(n)=sprp(n,2) && sprp(n,3) && sprp(n,5) && sprp(n,7) && !isprime(n) \\ _Charles R Greathouse IV_, Sep 14 2015 %Y A074773 Cf. A001262, A020229, A020231, A020233, A056915. %K A074773 nonn %O A074773 1,1 %A A074773 _Don Reble_, Sep 07 2002 %E A074773 b-file, link, and editing from _Charles R Greathouse IV_, Aug 14 2010