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A085557 Numbers that have more prime digits than nonprime digits. 5

%I #26 Apr 13 2024 20:08:10

%S 2,3,5,7,22,23,25,27,32,33,35,37,52,53,55,57,72,73,75,77,122,123,125,

%T 127,132,133,135,137,152,153,155,157,172,173,175,177,202,203,205,207,

%U 212,213,215,217,220,221,222,223,224,225,226,227,228,229,230,231,232

%N Numbers that have more prime digits than nonprime digits.

%C Begins to differ from A046034 at the 21st term (which is the first 3-digit term).

%H David A. Corneth, <a href="/A085557/b085557.txt">Table of n, a(n) for n = 1..10000</a>

%e 133 is in the sequence as the prime digits are 3 and 3 (those are two digits; counted with multiplicity) and one nonprime digit 1 and so there are more prime digits than nonprime digits. - _David A. Corneth_, Sep 06 2020

%o (PARI) is(n) = my(d = digits(n), c = 0); for(i = 1, #d, if(isprime(d[i]), c++)); c<<1 > #d \\ _David A. Corneth_, Sep 06 2020

%o (Python)

%o from itertools import count, islice

%o def A085557_gen(startvalue=1): # generator of terms

%o return filter(lambda n:len(s:=str(n))<(sum(1 for d in s if d in {'2','3','5','7'})<<1),count(max(startvalue,1)))

%o A085557_list = list(islice(A085557_gen(),20)) # _Chai Wah Wu_, Feb 08 2023

%Y Cf. A193238, A046034, A046035, A118950, A019546, A203263, A035232, A039996, A085823, A052382, A084544, A084984, A017042, A001743, A001744, A014261, A014263, A202267, A202268, A211681.

%K nonn,easy,base

%O 1,1

%A _Jason Earls_, Jul 04 2003

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Last modified July 19 20:58 EDT 2024. Contains 374436 sequences. (Running on oeis4.)