A048886 Numbers n such that sigma(n) = n-th composite number.

6, 8, 10, 14, 27, 39, 51, 57, 745, 755, 7091, 268243, 439681, 3271489, 33559819, 74138989, 80194627, 179405777, 1131818923, 1170569879, 1324475807, 1324478657, 51086967247, 72229691441, 72229691533, 72229691993, 72229693511

Offset

1,1

Links

Table of n, a(n) for n=1..27.

Prog

(PARI) isok(n) = (sigma(n) == A002808(n)) \\ (see script there). Michel Marcus, Jul 14 2013

Crossrefs

Cf. A002808, A000203.

Sequence in context: A243537 A073582 A363837 * A349477 A161545 A350295

Adjacent sequences: A048883 A048884 A048885 * A048887 A048888 A048889

Keyword

nonn

Author

Naohiro Nomoto

Extensions

a(15)-a(22) from Donovan Johnson, Apr 03 2008

a(23)-a(27) from Donovan Johnson, Oct 24 2010

Status

approved