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Squarefree kernel of A255334: a(n) = A007947(A255334(n)).
6

%I #7 Apr 14 2015 10:27:03

%S 42,210,462,546,714,798,966,210,1218,78,1302,1554,1722,1806,1974,2226,

%T 2310,2478,2562,2730,2814,2982,3066,3318,3486,3570,3738,3990,4074,

%U 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

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

%C 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.

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

%H Antti Karttunen, <a href="/A255424/b255424.txt">Table of n, a(n) for n = 1..6589</a>

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

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

%o (Scheme) (define (A255424 n) (A007947 (A255334 n)))

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

%K nonn

%O 1,1

%A _Antti Karttunen_, Apr 06 2015