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A134705 a(n) = n-th perfect number divided by 2^n. 2
3, 7, 62, 508, 1048448, 134216704, 1073739776, 9007199250546688, 5192296858534827626278696515534848, 187072209578355573530071658285452771612302071824384 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..10.

Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos.

FORMULA

a(n)=A000396(n)/(2^n).

EXAMPLE

a(3)=62 because the 3rd perfect number is 496 and 2^3=8 and 496/8=62.

MAPLE

perfp := [1, 2, 4, 6, 12, 16, 18, 30, 60, 88, 106, 126, 520, 606, 1278, 2202, 2280, 3216, 4252] : A000396 := proc(n) global perfp ; 2^op(n, perfp)*(2^(op(n, perfp)+1)-1) ; end: A134705 := proc(n) A000396(n)/2^n ; end: seq(A134705(n), n=1..12) ; # R. J. Mathar

CROSSREFS

Cf. A000396, A133028.

Sequence in context: A255669 A258184 A077703 * A110433 A219845 A041817

Adjacent sequences:  A134702 A134703 A134704 * A134706 A134707 A134708

KEYWORD

nonn

AUTHOR

Omar E. Pol, Nov 07 2007

EXTENSIONS

More terms from R. J. Mathar, Jan 07 2008

STATUS

approved

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Last modified May 20 20:16 EDT 2019. Contains 323426 sequences. (Running on oeis4.)