login
First differences of perfect numbers A000396, divided by 2.
11

%I #14 Oct 20 2023 08:40:18

%S 11,234,3816,16771104,4278159360,64424411136,1152921435350630400,

%T 1329227995784915871174424803906945024,

%U 95780971304118052318168693257235946738152352797163520

%N First differences of perfect numbers A000396, divided by 2.

%H Paolo Xausa, <a href="/A139229/b139229.txt">Table of n, a(n) for n = 1..14</a>

%F a(n) = A139228(n)/2.

%t Differences[Select[Range[10000], DivisorSigma[1, #] == 2# &]]/2 (* _Alonso del Arte_, Mar 05 2020 *)

%t Differences[PerfectNumber[Range[12]]]/2 (* _Paolo Xausa_, Oct 20 2023 *)

%Y Cf. A000396, A139228, A139230, A139231, A139232, A139233, A139234, A139235, A139236, A139237.

%K nonn

%O 1,1

%A _Omar E. Pol_, Apr 19 2008

%E a(6)-a(9) from A139228(n)/2 by _Jinyuan Wang_, Mar 04 2020