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 A287353 #33 Jan 07 2025 08:35:58
%S A287353 0,2,23,235,2357,23581,235823,2358247,23582489,235824913,2358249159,
%T A287353 23582491621,235824916247,2358249162511,23582491625153,
%U A287353 235824916251577,2358249162515823,23582491625158289
%N A287353 a(0)=0; for n>0, a(n) = 10*a(n-1) + prime(n).
%H A287353 Michael De Vlieger, <a href="/A287353/b287353.txt">Table of n, a(n) for n = 0..1000</a>
%F A287353 a(n) = Sum_{i=1..n} 10^(n-i)*prime(i), n >= 1. - _Ya-Ping Lu_, Dec 24 2024
%t A287353 FoldList[10 #1 + Prime@ #2 &, 0, Range@ 17] (* _Michael De Vlieger_, May 24 2017 *)
%o A287353 (Python)
%o A287353 from sympy import prime
%o A287353 l = [0]
%o A287353 for i in range(20):
%o A287353 l += [10 * l[i] + prime(i + 1)]
%o A287353 print(l) # _Indranil Ghosh_, May 25 2017
%o A287353 (PARI) a(n) = fromdigits(primes(n)); \\ _Kevin Ryde_, Jun 22 2022
%Y A287353 Cf. A014824, A019518, A092844, A110299.
%Y A287353 Cf. A379426 (prime terms).
%K A287353 nonn,easy
%O A287353 0,2
%A A287353 _Luke Zieroth_, May 23 2017