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 A107605 #13 Jun 08 2016 08:06:45 %S A107605 3,5,8,9,12,86,105,147,176,214,230,241,355,412,503,696,1065,1147,1170, %T A107605 1273,1334,2021,2455,2600,2660,2772,3299,3332,3365,4417,4861,6288, %U A107605 6478,6572,8115,8858,8905,9229,9380,9590,9692,9749,10501,10829,11338,11633 %N A107605 Numbers n such that prime(n) + n is a perfect power. %e A107605 Prime(8) + 8 = 19 + 8 = 27 = 3^3. %t A107605 f[n_] := Prime[n] + n; Select[Range[10^4], ! GCD @@ Last /@ FactorInteger[f[ # ]] == 1 &] (* _Ray Chandler_, May 21 2005 *) %o A107605 (Sage) [n for n in (1..10000) if (n+nth_prime(n)).is_perfect_power()] # _Giuseppe Coppoletta_, Jun 08 2016 %Y A107605 Cf. A001597 (perfect powers), A107606 (associated prime(n)+n), A107607, A107608, A109314. %K A107605 nonn %O A107605 1,1 %A A107605 _Zak Seidov_, May 17 2005 %E A107605 Extended by _Ray Chandler_, May 21 2005