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 A216872 Numbers n such that 2^n in decimal has at least 8 of the digits 0-9 appearing a prime number times. 1
 59, 67, 88, 104, 107, 108, 113, 114, 118, 120, 141, 146, 150, 156, 190, 214, 444, 880628 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Heuristically, all digits appear a prime number of times for an infinite number of values of n.  A216873 contains the subset with 9 in place of 8. a(19) > 5000000. - James G. Merickel, Apr 17 2015 LINKS PROG (PARI) /* program prints asterisks for values giving 9 instead of just 8,   and stops if all digits appear a prime number of times. */ { a=2; p=1; while(p, b=a; c=vectorsmall(10); while(b, d=b%10; b\=10; c[d+1]++; next()); e=3; for(i=1, 10, if(isprime(c[i])==0, e--; if(e==0, break()))); if(e, print1(p); if(e>1, print1("*"); if(e==3, break())); print1("\n")); p++; a+=a; next()) } CROSSREFS Cf. A216873. Sequence in context: A048988 A087766 A096339 * A235225 A015979 A065208 Adjacent sequences:  A216869 A216870 A216871 * A216873 A216874 A216875 KEYWORD nonn,base,hard AUTHOR James G. Merickel, Sep 18 2012 EXTENSIONS a(18) added by James G. Merickel, Jul 07 2013 STATUS approved

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Last modified November 27 09:19 EST 2021. Contains 349365 sequences. (Running on oeis4.)