A223613 Numbers k whose abundance is 24: sigma(k) - 2*k = 24.

112, 6592, 124672, 33452032, 82364907508, 36893488040044920832, 9444732964021303508992

Offset: 1

Author

Donovan Johnson, Mar 23 2013

Keywords

• nonn
• hard
• more

Comments

Suggested by N. J. A. Sloane and Robert G. Wilson v.

Every number of the form 2^(j-1)*(2^j - 25), where 2^j - 25 is prime, is a term (cf. A379020). - Jon E. Schoenfield, Jun 02 2019

Also contains 269113900901410149234393088. - Max Alekseyev, May 28 2025

Examples

			For k = 82364907508, sigma(k) - 2*k = 24.
		

Crossrefs

Cf. A000203, A033880, A379020.

Programs

PARI

for(n=1, 10^8, if(sigma(n)-2*n==24, print1(n ", ")))

Extensions

a(6) from Jon E. Schoenfield confirmed and a(7) added by Max Alekseyev, Jun 06 2025