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A217408 3-adic valuation of A217407. 2
35, 20, 59, 42, 63, 5, 69, 73, 21, 43, 71, 1149 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
See main sequence for rationale.
LINKS
EXAMPLE
The first number that has only 3 and 5 as prime factors and has prime counts of each digit 0-9 in its decimal representation is (3^35)*(5^17), so, corresponding to that being A217407(1), this sequence's first term is 35.
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(5), t=5^a; while(t<=lim, if(prDigits(t), listput(v, t)); t*=3)); apply(k -> valuation(k, 3), vecsort(Vec(v))) \\ Charles R Greathouse IV, Sep 19 2013
CROSSREFS
Sequence in context: A088830 A033355 A267402 * A266057 A267341 A174027
KEYWORD
nonn,base,less
AUTHOR
James G. Merickel, Oct 02 2012
STATUS
approved

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Last modified April 24 22:17 EDT 2024. Contains 371964 sequences. (Running on oeis4.)