A276729 - OEIS

%I #21 Sep 06 2019 15:10:16

%S 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 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 2,2,1,1,0,0,1,0,1,0,1,1,2,2,1,1,2,1,2,1,2,2,2

%N Number of nonprime digits in the decimal expansion of n.

%H Robert Israel, <a href="/A276729/b276729.txt">Table of n, a(n) for n = 0..10000</a>

%F a(n) = A055642(n) - A193238(n).

%F a(A046034(n)) = 0. - _Gordon Atkinson_, Sep 06 2019

%p f:= proc(n) local t; option remember;

%p   t:= n mod 10;

%p procname((n-t)/10) + `if`(member(t,[2,3,5,7]),0,1)

%p end proc:

%p f(0):= 0:

%p 1,seq(f(i),i=1..100); # _Robert Israel_, Feb 27 2019

%o (PARI) a(n)=#select(t->!isprime(t),digits(n))

%Y Cf. A055642, A193238, A085557, A046034 (indices of 0's), A084984, A085558, A202267, A202268.

%Y Cf. A011557 (integers that give records).

%K nonn,base,easy

%O 0,11

%A _M. F. Hasler_, Sep 16 2016