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.
Join[{0}, Select[Range[1000], PrimeQ[2*#^# + 1] &]] (* Robert Price, Mar 27 2019 *)
is_A110932(n)=ispseudoprime(n^n*2+1) \\ M. F. Hasler, Sep 02 2012
Flatten[{0, Select[Range[1000], PrimeQ[4*#^# + 3] &]}] (* Vaclav Kotesovec, Mar 25 2018 *)
for(n=0, 100, if(isprime(4*n^n+3), print1(n", ")))
a(1) = 1, because 2^2*3+1 = 13 is the smallest prime of this form. a(2) = 2, because 4^4*3+1 = 769 is the next smallest prime of this form. a(3) = 3, because 6^6*3+1 = 139969 is again a prime.
q:= k-> isprime(3*(2*k)^(2*k)+1): select(q, [$1..225])[]; # Alois P. Heinz, Aug 04 2025
for(i=1,9999,ispseudoprime(i^i*3+1)&print1(i/2,","))
for(n=0, 500, if(isprime(6*n^n+5), print1(n", ")))
Indices n = 0,1,2,3 correspond to the 4 primes a(n) = 3*(2n+1)^(2n+1) + 2, and to A160360(2,3,4,5) = 1,3,5,7. The next prime is a(46), with 184 digits too large to be displayed here. a(22)=1531477446517 is the smaller factor of the semiprime 3*45^45+2.
Table[FactorInteger[3(2n+1)^(2n+1)+2][[1,1]],{n,0,40}] (* Harvey P. Dale, Jan 25 2025 *)
forstep(n=1,300,2,forprime(p=1,default(primelimit),Mod(n,p)^n*3+2&next;print1(p",");next(2));print1(factor(3*n^n+2)[1,1]","))
Select[Range[1, 1000], PrimeQ[5*#^# + 4] &] (* Vaclav Kotesovec, Apr 01 2018 *)
for(n=0, 500, if(isprime(5*n^n+4), print1(n", ")))
lista(nn) = forstep(n=1, nn, 2, if(ispseudoprime(5*n^n+4), print1(n, ", "))); \\ Altug Alkan, Apr 01 2018
Table[FactorInteger [((2 n + 1)^(2 n + 1) + 2)][[1, 1]], {n, 0, 46}] (* Vincenzo Librandi, Feb 24 2014 *)
FactorInteger[#^#+2][[1,1]]&/@Range[1,91,2] (* Harvey P. Dale, Aug 27 2023 *)
A228613=n->factor((2*n+1)^(2*n+1)+2)[1,1]
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