A379122 Odd numbers m for which A379113(m^2) > 1, i.e., k = m^2 has a proper unitary divisor d > 1 such that A048720(A065621(sigma(d)),sigma(k/d)) is equal to sigma(k).

15, 55, 57, 111, 171, 195, 303, 465, 497, 595, 639, 867, 879, 925, 959, 1169, 1263, 1953, 3135, 3345, 3489, 3565, 5425, 6923, 7239, 8153, 8215, 8801, 8959, 9703, 10033, 10507, 11249, 14291, 16275, 18135, 18569, 18693, 19173, 20271, 23943, 24303, 26607, 28325, 32581, 33655, 34163, 40393, 43927, 46221, 47649, 55281

Offset: 1

Author

Antti Karttunen, Dec 18 2024

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..2025
• Index entries for sequences defined by congruent products between domains N and GF(2)[X].
• Index entries for sequences related to polynomials in ring GF(2)[X].
• Index entries for sequences related to sigma(n).

Crossrefs

Square roots of A379121.

Cf. A379113.

Programs

PARI

is_A379122(n) = (n%2 && A379113(n^2)>1);

Formula

{Odd k such that A379113(k^2) > 1}.

a(n) = A000196(A379121(n)).