A217405 2-adic valuation of A217404.

36, 28, 54, 10, 87, 10, 20, 1, 59, 121, 97, 134, 135, 88, 131, 175, 58, 66

Offset

1,1

Comments

See the main sequence corresponding to this one, A217404.

Links

Table of n, a(n) for n=1..18.

Example

A217404(1)=(2^36)*(7^15), so that the exponent on 2, 36, is the first term here.

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, 2), vecsort(Vec(v))) \\ Charles R Greathouse IV, Sep 19 2013

Crossrefs

Cf. A217404, A217406.

Sequence in context: A083819 A358173 A194941 * A291472 A291493 A326585

Adjacent sequences: A217402 A217403 A217404 * A217406 A217407 A217408

Keyword

nonn,base

Author

James G. Merickel, Oct 02 2012

Status

approved