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 A276729 #21 Sep 06 2019 15:10:16 %S A276729 1,1,0,0,1,0,1,0,1,1,2,2,1,1,2,1,2,1,2,2,1,1,0,0,1,0,1,0,1,1,1,1,0,0, %T A276729 1,0,1,0,1,1,2,2,1,1,2,1,2,1,2,2,1,1,0,0,1,0,1,0,1,1,2,2,1,1,2,1,2,1, %U A276729 2,2,1,1,0,0,1,0,1,0,1,1,2,2,1,1,2,1,2,1,2,2,2 %N A276729 Number of nonprime digits in the decimal expansion of n. %H A276729 Robert Israel, <a href="/A276729/b276729.txt">Table of n, a(n) for n = 0..10000</a> %F A276729 a(n) = A055642(n) - A193238(n). %F A276729 a(A046034(n)) = 0. - _Gordon Atkinson_, Sep 06 2019 %p A276729 f:= proc(n) local t; option remember; %p A276729 t:= n mod 10; %p A276729 procname((n-t)/10) + `if`(member(t,[2,3,5,7]),0,1) %p A276729 end proc: %p A276729 f(0):= 0: %p A276729 1,seq(f(i),i=1..100); # _Robert Israel_, Feb 27 2019 %o A276729 (PARI) a(n)=#select(t->!isprime(t),digits(n)) %Y A276729 Cf. A055642, A193238, A085557, A046034 (indices of 0's), A084984, A085558, A202267, A202268. %Y A276729 Cf. A011557 (integers that give records). %K A276729 nonn,base,easy %O A276729 0,11 %A A276729 _M. F. Hasler_, Sep 16 2016