A082129 Rounded base-2 logarithm of A082128(n+4).

3, 1, 5, 4, 6, 9, 17, 22, 33, 53, 76, 114, 171, 260, 390, 585, 874, 1311, 1970

Offset: 0

Author

Ralf Stephan, Apr 04 2003

Keywords

• nonn
• hard

Crossrefs

Cf. A082127, A082128.

Programs

PARI

p=21*4*5*13; for(n=1, 50, v=divisors(p); r=sqrt(p); t=0; for(k=1, matsize(v)[2], if(v[k]>=r, t=k; break)); if(v[t]^2==p, u=t, u=t-1); if(v[t]-v[u]<2, u=u-1; t=t+1); print1(round(log(v[t]-v[u])/log(2))", "); p=p*(v[t]-v[u]))