OFFSET

1,2

COMMENTS

PROG

(PARI)

allocatemem(2^30);

default(parisizemax, 2^31);

up_to = (2^25)+2;

A061395(n) = if(1==n, 0, primepi(vecmax(factor(n)[, 1])));

m_inverses = Map();

q2 = 0; prev=1; for(n=1, up_to, found_it = 0; fordiv(prev, d, if(!mapisdefined(m_inverses, (prev/d)), found_it = (prev/d); mapput(m_inverses, (prev/d), n); break)); if(!found_it, apu = prev; while(mapisdefined(m_inverses, try = prev*A053669(apu)), apu *= A053669(apu)); found_it = try; mapput(m_inverses, try, n)); if((q1=A061395(found_it)) != q2, write("b302774.txt", q1, " ", n-1); write("b302775.txt", q1, " ", found_it)); prev = found_it; q2 = q1);

CROSSREFS

KEYWORD

nonn

AUTHOR

Antti Karttunen, May 04 2018

STATUS

approved