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 A202259 #22 Nov 02 2016 03:47:49 %S A202259 0,1,4,6,8,9,10,12,14,15,16,18,40,42,44,45,46,48,49,60,62,63,64,65,66, %T A202259 68,69,80,81,82,84,85,86,87,88,90,91,92,93,94,95,96,98,99,100,102,104, %U A202259 105,106,108,120,121,122,123,124,125,126,128,129,140,141,142 %N A202259 Right-truncatable nonprimes: every prefix is nonprime number. %C A202259 Supersequence of A202260, A202265. - _Barry Carter_, Sep 16 2016 %H A202259 Robert Israel, <a href="/A202259/b202259.txt">Table of n, a(n) for n = 1..10000</a> %H A202259 Barry Carter, <a href="https://github.com/barrycarter/bcapps/blob/master/QUORA/A202259.b.txt.bz2">Table of n, a(n) for n=1..23498959</a> (bz2 compressed) %H A202259 Barry Carter, <a href="https://github.com/barrycarter/bcapps/blob/master/QUORA/A202259.m">Mathematica package</a> %p A202259 filter:= proc(n) option remember; not isprime(n) and procname(floor(n/10)) end proc: %p A202259 for i from 0 to 9 do filter(i):= not isprime(i) od: %p A202259 select(filter, [$0..1000]); # _Robert Israel_, Nov 01 2016 %Y A202259 Cf. A012883 (right-truncatable noncomposites), A024770 (right-truncatable primes), A202260 (right-truncatable composites). %K A202259 nonn,base %O A202259 1,3 %A A202259 _Jaroslav Krizek_, Dec 25 2011