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 A267819 #17 Jun 29 2019 01:41:50 %S A267819 89,139,4801,6829,9601,48661,305551,539849,867001,3503449,3527071, %T A267819 6063839,13912039,15933439,18100351,18319321,20366399,22849121, %U A267819 26239321,46724801,63565049,78057911,95802799,100294871,102369439,107474911,139769449,141118079,144829879,159468079,161483801 %N A267819 Primes whose base-5 representation is a square when read in base 10. %C A267819 Primes in the sequence A267765. %H A267819 Chai Wah Wu, <a href="/A267819/b267819.txt">Table of n, a(n) for n = 1..10000</a> %e A267819 89 in base 5 is 324, and 324 = 18^2 in base 10. %t A267819 Select[Prime@ Range[10^6], IntegerQ@ Sqrt@ FromDigits@ IntegerDigits[#, 5] &] (* _Michael De Vlieger_, Jan 24 2016 *) %o A267819 (Python) %o A267819 from sympy import isprime %o A267819 A267819_list = [int(d,5) for d in (str(i**2) for i in range(1,10**6)) if max(d) < '5' and isprime(int(d,5))] # _Chai Wah Wu_, Feb 22 2016 %Y A267819 In other bases: A267817 - A267821, A241246, A267490. %K A267819 nonn,base %O A267819 1,1 %A A267819 _Christopher Cormier_, Jan 20 2016