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.
[ n: n in [0..300] | IsPrime((Factorial(n)^4)+1)] // Vincenzo Librandi, Dec 22 2010
Select[Range[200], PrimeQ[#!^4 + 1] &]
a(1) = 1 has digsum = 1, therefore a(2) = 2, the smallest novel multiple of 1+1 = 2. Likewise, a(n) = n for all n <= 10. a(11) = 12 because 1 + digsum(10) = 2 and 12 is the smallest number not already a term which is divisible by 2. a(20) = 28, and digsum(28) + 1 = 11. Therefore a(21) = 11 because 28 is the first occasion of digsum(a(n-1)) = 10.
nn = 10^4; j = 1; u = 2; c[] := False; m[] := 1; {j}~Join~Reap[Do[ k = u; d = DigitSum[j] + 1; While[c[Set[k, m[d]*d]], m[d]++]; Set[{j, c[k]}, {k, True}]; Sow[k]; If[k == u, While[c[u], u++]], {n, 2, nn}] ][[-1, 1]]
Do[f=(n!)^8+1;If[PrimeQ[f],Print[{n,f}]],{n,1,75}]
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