1,1

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

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

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

# see http://www-maths.swan.ac.uk/pgrads/bb/project/node43.html 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

Cf. A000396, A133028.

Sequence in context: A046859 A084289 A077703 this_sequence A110433 A041817 A120364

Adjacent sequences: A134702 A134703 A134704 this_sequence A134706 A134707 A134708

nonn

Omar E. Pol (info(AT)polprimos.com), Nov 07 2007

More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 07 2008