A048886 - OEIS

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

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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