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A326183 Numbers n for which A003961(n) <= A064989(sigma(A003961(n))), but which are not squares. 1
97560000, 140040000, 161640000, 188280000, 392760000, 414360000, 429480000, 432360000, 443160000, 474840000, 494280000, 522360000, 582840000, 589320000, 673560000, 715320000, 767160000, 842040000, 888120000, 903960000, 918360000, 932760000, 1026360000, 1047240000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

At least for 1 <= n <= 24 it holds that A052126(a(n)) is square, and moreover, apart from a(20), that square is 360000, while A052126(a(20)) = A052126(903960000) = 29160000.

The largest prime factors (that are also unitary in case of 24 initial terms) are A006530(a(n)): 271, 389, 449, 523, 1091, 1151, 1193, 1201, 1231, 1319, 1373, 1451, 1619, 1637, 1871, 1987, 2131, 2339, 2467, 31, 2551, 2591, 2851, 2909.

LINKS

Table of n, a(n) for n=1..24.

Index entries for sequences computed from indices in prime factorization

Index entries for sequences related to sigma(n)

CROSSREFS

Setwise difference A326182 \ A000290.

Cf. A000203, A003961, A006530, A052126, A064989.

Sequence in context: A250964 A075010 A214559 * A184151 A096710 A322682

Adjacent sequences:  A326180 A326181 A326182 * A326184 A326185 A326186

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jun 17 2019

STATUS

approved

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Last modified November 13 15:41 EST 2019. Contains 329106 sequences. (Running on oeis4.)