

A309553


Imperfect numbers of the form 2^(2^k1)*F_1*F_2*...*F_(k1), where F is a Fermat number.


0




OFFSET

1,1


COMMENTS

Numbers of this form are imperfect only for k = 2, 3, 4, 5.


LINKS

Table of n, a(n) for n=1..4.
László Tóth, A survey of the alternating sumofdivisors function, arXiv:1111.4842 [math.NT], 20112014, end of section 8.
László Tóth, A survey of the alternating sumofdivisors function, Acta Universitatis Sapientiae, Mathematica, Vol. 5, No. 1 (2013), pp. 93107.


EXAMPLE

For k=2, 2^3*F_1 = 8*5 = 40, so 40 is in the sequence.


CROSSREFS

Cf. A000215, A127724.
Sequence in context: A183766 A184892 A119525 * A123381 A210347 A221391
Adjacent sequences: A309550 A309551 A309552 * A309554 A309555 A309556


KEYWORD

nonn,fini,full


AUTHOR

Jud McCranie, Aug 07 2019


STATUS

approved



