A217406 7-adic valuation of A217404.

15, 19, 13, 29, 3, 34, 31, 43, 24, 2, 14, 11, 11, 29, 14, 4, 55, 89

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