This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A082459 #8 Jan 11 2018 23:47:07 %S A082459 -1,-1,0,0,2,6,9,36,40,200,205,1230,1236,8652,8659,69272,69280,623520, %T A082459 623529,6235290,6235300,68588300,68588311,823059732,823059744, %U A082459 10699776672,10699776685,149796873590,149796873604,2246953104060,2246953104075,35951249665200,35951249665216 %N A082459 Multiply by 1, add 1, multiply by 2, add 2, etc. %C A082459 Bisections: A038156 and A038157. %H A082459 Robert Israel, <a href="/A082459/b082459.txt">Table of n, a(n) for n = 0..898</a> %F A082459 From _Robert Israel_, Jan 11 2018: (Start) %F A082459 a(2*k) = e*Gamma(k+1,1) - k! - 1. %F A082459 a(2*k+1) = e*Gamma(k+2,1) - (k+1)! - k - 2. (End) %p A082459 seq(op(simplify([exp(1)*GAMMA(k+1,1)-k!-1, exp(1)*GAMMA(k+2,1)-(k+1)!-k-2])),k=0..20); # _Robert Israel_, Jan 11 2018 %t A082459 FoldList[If[OddQ@ #2, #1 ((#2 + 1)/2), #1 + #2/2] &, -1, Range@ 31] (* _Michael De Vlieger_, Jan 11 2018 *) %Y A082459 Cf. A019464 - A019466. %K A082459 sign %O A082459 0,5 %A A082459 _Vladeta Jovovic_, Apr 25 2003