A241650 Numbers m such that the GCD of the x's that satisfy sigma(x) = m is 5.

6, 22152, 35724, 125892, 132444, 146484, 166764, 182052, 192504, 202332, 239304, 242580, 248664, 267852, 291252, 300612, 375492, 375804, 434772, 460044, 494364, 536952, 547992, 550524, 618852, 628212, 646668, 707304, 708984, 752232, 777852, 824304, 828984

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..5000

Max Alekseyev, PARI/GP Scripts for Miscellaneous Math Problems (invphi.gp).

Example

Only sigma(5) = 6, with gcd(5) = 5, so 6 is in the sequence.
Also, sigma(12735) = sigma(18455) = 22152, and gcd(12735, 18455) = 5, hence 22152 is in the sequence.

Prog

(PARI) is(k) = gcd(invsigma(k)) == 5; \\ Amiram Eldar, Dec 19 2024, using Max Alekseyev's invphi.gp

Crossrefs

Cf. A000203, A240667, A241625, A241646, A241647, A241648, A241649.

Sequence in context: A278653 A376824 A283887 * A368064 A337990 A143780

Adjacent sequences: A241647 A241648 A241649 * A241651 A241652 A241653

Keyword

nonn,changed

Author

Michel Marcus, Apr 26 2014

Status

approved