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 A113650 #44 Feb 16 2025 08:32:59 %S A113650 2,3,5,21,55,39,272,57,345,754,775,481,1599,1677,752,1484,590,2928, %T A113650 469,3905,4234,3871,1743,445,3589,9797,2266,2568,2834,6780,1651,8384, %U A113650 7946,16263,17880,9060,6908,26080,7348,22490,31146,23711,17954,5983 %N A113650 Fibonacci(p-J(p,5)) mod p^2, where p is the n-th prime and J is the Jacobi symbol. %C A113650 A value of 0 indicates a Wall-Sun-Sun prime. No such prime is currently known. - _Felix Fröhlich_, Jun 07 2014 %H A113650 T. D. Noe, <a href="/A113650/b113650.txt">Table of n, a(n) for n = 1..10000</a> %H A113650 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Wall-Sun-SunPrime.html">Wall-Sun-Sun Prime</a> %t A113650 a[n_]:= ( p=Prime[n];Mod[Fibonacci[p-JacobiSymbol[p, 5]], Power[p, 2]]); Table[a[n], {n,1,50}] (* _Javier Rivera Romeu_, Mar 03 2022 *) %o A113650 (PARI) a(n)=my(p=prime(n));lift(Mod([1,1;1,0]^(p-kronecker(p,5)),p^2)[1,2]) \\ _Charles R Greathouse IV_, Oct 31 2011 %o A113650 (Sage) %o A113650 def a(n): %o A113650 p = Primes().unrank(n-1) %o A113650 return fibonacci(p-jacobi_symbol(p, 5))%pow(p, 2) %o A113650 for n in range(1, 100): print(a(n), end=", ") # _Javier Rivera Romeu_, Mar 04 2022 %Y A113650 Cf. A113649. %K A113650 nonn %O A113650 1,1 %A A113650 _Eric W. Weisstein_, Nov 03 2005