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 A065537 #11 Jun 18 2018 03:26:16
%S A065537 7,71,719,7193,71933,719333,7193357,71933597,719335993,7193359933,
%T A065537 71933599363,719335993631,7193359936331,71933599363319,
%U A065537 719335993633291,7193359936332919,71933599363329217,719335993633292261
%N A065537 a(n) is smallest prime > 10*a(n-1), a(1) = 7.
%H A065537 Harry J. Smith, <a href="/A065537/b065537.txt">Table of n, a(n) for n = 1..100</a>
%t A065537 NextPrim[n_Integer] := Block[ {k = n + 1}, While[ !PrimeQ[k], k++ ]; Return[k]]; a[1] = 7; a[n_] := NextPrim[ 10*a[n - 1]]; Table[ a[n], {n, 1, 20} ]
%o A065537 (PARI) { for (n=1, 100, if (n>1, a=nextprime(10*a), a=7); write("b065537.txt", n, " ", a) ) } \\ _Harry J. Smith_, Oct 21 2009
%Y A065537 Cf. A065122, A048552.
%K A065537 nonn
%O A065537 1,1
%A A065537 _Robert G. Wilson v_, Nov 28 2001