A277893 A277893(n) = the least k > n for which A277892(k) = A277892(n), 0 if no such number exists.

0, 4, 6, 9, 8, 25, 10, 12, 18, 49, 14, 93, 15, 16, 20, 169, 22, 287, 21, 26, 24, 361, 30, 33, 27, 28, 34, 529, 32, 802, 40, 35, 36, 44, 38, 934, 39, 48, 42, 1333, 46, 1681, 45, 51, 54, 1754, 50, 58, 52, 55, 64, 2209, 56, 57, 66, 60, 65, 2809, 62, 2966, 63, 68, 74, 77, 70

Offset: 2

Author

Antti Karttunen, Nov 08 2016

Keywords

• nonn

Comments

a(n) is the least k larger than n for which the number of divisors of A048675(k) is equal to the number of divisors of A048675(n) (counted with multiplicity), and 0 if no such number exists (which happens only for n=2).

Links

• Antti Karttunen, Table of n, a(n) for n = 2..102 (computed from the b-file provided by Hans Havermann for A277892)

Crossrefs

Cf. A048675, A277892, A277894, A277898.

Programs

Scheme

(define (A277893 n) (cond ((= 2 n) 0) (else (let ((v (A277892 n))) (let loop ((k (+ 1 n))) (if (= (A277892 k) v) k (loop (+ 1 k))))))))

Formula

For n >= 3, A277894(a(n)) = n.