A303900 Numbers k such that the average of all strong divisors of all positive integers <= k is an integer.

2, 8, 12, 16, 67, 924122, 1067239

Offset

1,1

Comments

We say d is a strong divisor of k iff d is a divisor of k and d > 1.

Numbers k such that A002541(k) | A024917(k).

a(8) > 10^12. - Giovanni Resta, May 05 2018

Links

Table of n, a(n) for n=1..7.

Index entries for sequences related to divisors of numbers

Crossrefs

Cf. A024917, A027750, A032741, A039653, A056550, A226647, A284288, A284755, A303480, A303482, A303659.

Sequence in context: A005880 A290608 A340690 * A046470 A090772 A046525

Adjacent sequences: A303897 A303898 A303899 * A303901 A303902 A303903

Keyword

nonn,more

Author

Ilya Gutkovskiy, May 02 2018

Extensions

a(3)-a(7) corrected by Daniel Suteu, May 03 2018

Status

approved