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

0,1

Links

Table of n, a(n) for n=0..18.

Prog

(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]))

Crossrefs

Cf. A082127, A082128.

Sequence in context: A152747 A010847 A331698 * A363233 A159970 A096374

Adjacent sequences: A082126 A082127 A082128 * A082130 A082131 A082132

Keyword

nonn,hard

Author

Ralf Stephan, Apr 04 2003

Status

approved