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.
Flatten[Table[Select[FromDigits/@Tuples[{2,3},n],PrimeQ],{n,7}]] (* Harvey P. Dale, Jul 13 2012 *)
go(n)=my(v=List([2]),x,t); for(d=1,n, x=10^d\9*2; forstep(i=1,2^d-1,2, if(ispseudoprime(t=x+fromdigits(binary(i))), listput(v,t)))); Vec(v) \\ Charles R Greathouse IV, Sep 14 2015
from sympy import isprime
from itertools import count, islice, product
def agen(): # generator of terms
yield from [2, 3]
for d in count(2):
for first in product("23", repeat=d-1):
t = int("".join(first) + "3")
if isprime(t): yield t
print(list(islice(agen(), 34))) # Michael S. Branicky, Jun 08 2022
a = {}; Do[If[PrimeQ[(n! + 8)/8], AppendTo[a, n]], {n, 1, 500}]; a
is(n)=n>6 && isprime((8+n!)/8) \\ Charles R Greathouse IV, Apr 29 2016
a(3) = 23 because the third prime is 5 and 2 + 3 = 5. a(4) = 223 because the fourth prime is 7 and 2 + 2 + 3 = 7. a(5) = 2333 because the fifth prime is 11 and 2 + 3 + 3 + 3 = 11.
Module[{nn = 30, t1, t2}, t1 = FromDigits/@Select[Table[PadRight[{2}, n, 3], {n, 2, nn}], PrimeQ[Total[#]] &]; t2 = FromDigits/@ Select[ Table[ PadRight[{2, 2}, n, 3], {n, 2, nn}], PrimeQ[Total[#]] &]; Union[ Join[ {2, 3}, t1, t2]]] (* Harvey P. Dale, Mar 06 2013 *)
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