A276714 Numbers n such that n and n+3 have the same number and sum of divisors (A000005 and A000203).

42677635, 276742235, 6439057062, 7512673242

Offset

1,1

Comments

Intersection of A015861 and A276713.

Also numbers n such that A229335(n) = A229335(n+3).

Links

Table of n, a(n) for n=1..4.

Example

42677635 is in sequence because tau(42677635) = tau(42677638) = 32 and sigma(42677635) = sigma(42677638) = 68769792.

Prog

(Magma) [n: n in [A015861(k)] | NumberOfDivisors(n) eq  NumberOfDivisors(n+3) and SumOfDivisors(n) eq  SumOfDivisors(n+3)]

Crossrefs

Cf. A015861, A229335, A276713, A276715.

Cf. Similar sequences with numbers n such that n and n+k have the same number and sum of divisors for k=1: A054004, for k=2: A229254.

Sequence in context: A213737 A254091 A254098 * A187963 A028520 A288843

Adjacent sequences: A276711 A276712 A276713 * A276715 A276716 A276717

Keyword

nonn,more

Author

Jaroslav Krizek, Sep 16 2016

Status

approved