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 A116056 #8 Sep 13 2019 20:26:08 %S A116056 33,8833,66644,66777,117766,118811,990000,1144000,9997777,115522333, %T A116056 116660044,116661111,1100088555,1100088855,1100111100,1100111111, %U A116056 1100111333,1100112200,1100112211,1100112222,2277334444,2277334455,2277334466,2277334477,2277335500,2288811222 %N A116056 n and pi(n) are both made of nontrivial runs of identical digits, where pi(n)=A000720(n). %C A116056 A run of length 1 is trivial. %C A116056 Up to 10^18 there are only 5 prime terms: 9997777, 1122991155533399, 44770077777722233, 440009996622997711, 442244499338866333. - _Giovanni Resta_, Sep 13 2019 %H A116056 Giovanni Resta, <a href="/A116056/b116056.txt">Table of n, a(n) for n = 1..418</a> (terms < 10^18) %e A116056 pi(118811) = 11199, pi(9997777) = 664444. %t A116056 zyQ[n_] := Min[Length /@ Split[IntegerDigits[n]]] > 1; Select[Range[10^7], zyQ[#] && zyQ[PrimePi[#]] &] (* _Giovanni Resta_, Sep 13 2019 *) %Y A116056 Cf. A000720, A033023, A103357. %K A116056 nonn,base %O A116056 1,1 %A A116056 _Giovanni Resta_, Feb 13 2006 %E A116056 More terms from _Giovanni Resta_, Sep 13 2019