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 A217406 7-adic valuation of A217404. 2
 15, 19, 13, 29, 3, 34, 31, 43, 24, 2, 14, 11, 11, 29, 14, 4, 55, 89 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS See main sequence, A217404. LINKS Table of n, a(n) for n=1..18. EXAMPLE A217404(1)=(2^36)*(7^15), so this sequence's first term is 15, the exponent on 7 in the main sequence. PROG (PARI) prDigits(n)=my(d=digits(n), v=vector(10)); for(i=1, #d, v[d[i]+1]++); for(i=1, 10, if(!isprime(v[i]), return(0))); 1 list(lim)=my(v=List(), t); for(a=0, log(lim+.5)\log(7), t=7^a; while(t<=lim, if(prDigits(t), listput(v, t)); t<<=1)); apply(k -> valuation(k, 7), vecsort(Vec(v))) \\ Charles R Greathouse IV, Sep 19 2013 CROSSREFS Subsequence of A215876. Cf. A217404, A217405. Sequence in context: A222682 A220787 A167322 * A181664 A348517 A224535 Adjacent sequences: A217403 A217404 A217405 * A217407 A217408 A217409 KEYWORD nonn,base,more AUTHOR James G. Merickel, Oct 02 2012 STATUS approved

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Last modified October 4 22:13 EDT 2023. Contains 365888 sequences. (Running on oeis4.)