A326038 Square root of the largest square dividing the sum of divisors of n: a(n) = A000188(sigma(n)).

1, 1, 2, 1, 1, 2, 2, 1, 1, 3, 2, 2, 1, 2, 2, 1, 3, 1, 2, 1, 4, 6, 2, 2, 1, 1, 2, 2, 1, 6, 4, 3, 4, 3, 4, 1, 1, 2, 2, 3, 1, 4, 2, 2, 1, 6, 4, 2, 1, 1, 6, 7, 3, 2, 6, 2, 4, 3, 2, 2, 1, 4, 2, 1, 2, 12, 2, 3, 4, 12, 6, 1, 1, 1, 2, 2, 4, 2, 4, 1, 11, 3, 2, 4, 6, 2, 2, 6, 3, 3, 4, 2, 8, 12, 2, 6, 7, 3, 2, 1, 1, 6, 2, 1, 8

Offset

1,3

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for sequences related to sigma(n)

Formula

a(n) = A000188(A000203(n)) = A000196(A326039(n)).

Mathematica

Table[Last[Select[Sqrt[#]&/@Divisors[DivisorSigma[1, n]], IntegerQ]], {n, 120}] (* Harvey P. Dale, Jun 25 2022 *)

Prog

(PARI)
A000188(n) = core(n, 1)[2]; \\ From A000188
A326038(n) = A000188(sigma(n));

Crossrefs

Cf. A000188, A000196, A326038, A326039, A326040.

Sequence in context: A323023 A083415 A115514 * A122632 A176809 A317815

Adjacent sequences: A326035 A326036 A326037 * A326039 A326040 A326041

Keyword

nonn

Author

Antti Karttunen, Jun 05 2019

Status

approved