A054002 - OEIS

A054002

Number of divisors of n such that n and n-1 have the same sum of divisors.

4, 6, 4, 8, 16, 8, 8, 12, 12, 8, 4, 10, 8, 4, 8, 12, 8, 16, 16, 16, 16, 8, 16, 12, 16, 16, 8, 8, 4, 16, 8, 24, 16, 4, 16, 8, 4, 32, 8, 16, 16, 16, 8, 8, 8, 8, 16, 32, 8, 8, 16, 16, 16, 12, 16, 16, 12, 8, 48, 32, 8, 24, 24, 16, 16, 16, 8, 16, 24, 64, 8, 16, 16, 16, 16, 64, 24, 32, 60

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OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10135 (from the b-file at A002961)

FORMULA

a(n) = tau(A002961(n) + 1).

PROG

(Magma) [#Divisors(n):n in [2..3500000]| SumOfDivisors(n) eq SumOfDivisors(n-1)]; // Marius A. Burtea, Sep 07 2019

CROSSREFS

Cf. A000005, A000203, A002961, A053249, A054003.

Sequence in context: A055166 A202243 A130762 * A010300 A113209 A367731