A326183 Numbers n for which A003961(n) <= A064989(sigma(A003961(n))), but which are not squares.

97560000, 140040000, 161640000, 188280000, 392760000, 414360000, 429480000, 432360000, 443160000, 474840000, 494280000, 522360000, 582840000, 589320000, 673560000, 715320000, 767160000, 842040000, 888120000, 903960000, 918360000, 932760000, 1026360000, 1047240000

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