A145340 a(n) = the maximum of d(p(n)-1) and d(p(n)+1), where d(m) is the number of divisors of m and p(n) is the n-th prime.

2, 3, 4, 4, 6, 6, 6, 6, 8, 8, 8, 9, 8, 8, 10, 8, 12, 12, 8, 12, 12, 10, 12, 12, 12, 9, 8, 12, 12, 10, 12, 12, 8, 12, 12, 12, 12, 10, 16, 8, 18, 18, 14, 14, 12, 12, 16, 12, 12, 12, 12, 20, 20, 18, 9, 16, 16, 16, 12, 16, 8, 12, 12, 16, 16, 8, 16, 20, 12, 12, 12, 24, 10, 12, 16, 16, 16

Offset

1,1

Links

Table of n, a(n) for n=1..77.

Mathematica

Table[Max[DivisorSigma[0, Prime[n]-1], DivisorSigma[0, Prime[n]+1]], {n, 1, 100}] (* Stefan Steinerberger, Oct 11 2008 *)

Crossrefs

Cf. A145339, A008328, A008329, A067889, A103664, A103665.

Sequence in context: A096908 A162684 A265533 * A307989 A160680 A243069

Adjacent sequences: A145337 A145338 A145339 * A145341 A145342 A145343

Keyword

nonn

Author

Leroy Quet, Oct 08 2008

Extensions

More terms from Stefan Steinerberger and Ray Chandler, Oct 11 2008

Status

approved