A255424 Squarefree kernel of A255334: a(n) = A007947(A255334(n)).

42, 210, 462, 546, 714, 798, 966, 210, 1218, 78, 1302, 1554, 1722, 1806, 1974, 2226, 2310, 2478, 2562, 2730, 2814, 2982, 3066, 3318, 3486, 3570, 3738, 3990, 4074, 4242, 4326, 4494, 4578, 4746, 4830, 462, 210, 5334, 5502, 5754, 5838, 6006, 6090, 390, 6258, 6342, 6510, 6594, 6846, 7014, 546, 7266, 7518, 7602, 7770, 7854, 8022, 8106, 8274, 8358, 8610

Offset: 1

Author

Antti Karttunen, Apr 06 2015

Keywords

• nonn

Comments

Sequence gives value of A007947(n) for numbers n for which there exists k > n such that A000203(k) = A000203(n) and A007947(k) = A007947(n), where A000203 gives the sum of divisors, and A007947 gives the squarefree kernel of n. The sequence is ordered according to the magnitude of n, and contains duplicates, because there are cases of multiple such pairs having same squarefree kernel.

The first duplicate occurs as a(2) = a(8) = 210.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..6589

Crossrefs

Cf. A007947, A255334, A255412, A255423, A255425, A255426.

Programs

Scheme

(define (A255424 n) (A007947 (A255334 n)))

Formula

a(n) = A007947(A255334(n)).

a(n) = A007947(A255423(n)). [Equally, squarefree kernel of A255423(n).]