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A052396 (+2)-sigma perfect numbers: numbers such that (+2)sigma(n)=2*n, where if n=Product p(i)^r(i) then (+2)sigma(n)=Product (2+Sum p(i)^s(i), s(i)=1 to r(i)), e.g. (+2)sigma(6)=(2+2)*(2+3)=20. 2
2, 4, 8, 16, 32, 63, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 34587, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 170271081 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..30.

EXAMPLE

Factorizations: even examples 2,2^2,2^3,2^4,...; odd examples 3^2*7 a(6), 3^4*7*61 a(17), 3^6*7*61*547 a(30).

CROSSREFS

Sequence in context: A283837 A111663 A054043 * A051040 A006261 A290987

Adjacent sequences:  A052393 A052394 A052395 * A052397 A052398 A052399

KEYWORD

nonn

AUTHOR

Yasutoshi Kohmoto Mar 13 2000

EXTENSIONS

Corrected by Franklin T. Adams-Watters, Oct 25 2006

STATUS

approved

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Last modified December 11 03:29 EST 2018. Contains 318049 sequences. (Running on oeis4.)