A054006 Number of divisors of k and k+1 which have the same number and sum of divisors.

4, 8, 8, 8, 8, 8, 16, 16, 16, 8, 16, 16, 16, 16, 16, 16, 16, 16, 32, 16, 16, 16, 16, 32, 16, 16, 16, 24, 16, 16, 16, 32, 32, 32, 16, 16, 32, 16, 32, 16, 16, 32, 32, 16, 32, 16, 16, 16, 16, 16, 32, 32, 16, 32, 16, 16, 64, 32, 16, 32, 16, 32, 16, 64, 32, 32, 16, 32, 32, 32, 32

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..1831 (calculated using the b-file at A054004)

Formula

a(n) = tau(A054004(n)).

Example

See example in A054004.

Mathematica

Select[Partition[Array[DivisorSigma[{0, 1}, #] &, 10^6], 2, 1], SameQ @@ # &][[All, 1, 1]] (* Michael De Vlieger, Nov 21 2019 *)

Crossrefs

Cf. A000005, A000203, A002961, A005237, A053249, A054004, A054005, A054007.

Sequence in context: A201405 A331067 A040012 * A394511 A029679 A304651

Adjacent sequences: A054003 A054004 A054005 * A054007 A054008 A054009

Keyword

nonn

Author

Asher Auel, Jan 12 2000

Extensions

More terms from Jud McCranie, Oct 15 2000

Status

approved