|
%I #9 Jul 13 2013 12:03:27
%S 2,5,8,11,12,14,17,19,20,23,29,30,32,33,35,38,40,44,50,52,53,54,59,61,
%T 62,63,65,75,77,80,82,83,85,90,92,95,98,103,104,109,113,117,118,119,
%U 122,124,125,129,132,134,137,138,143,145,147,149,151,158,159,162,164,167
%N Numbers that can be written uniquely as 4*x*y-x-y with 1<=x<=y.
%C A125203(a(n)) = 1.
%C A124934 is the union of this sequence and A125218.
%H Reinhard Zumkeller, <a href="/A125217/b125217.txt">Table of n, a(n) for n = 1..10000</a>
%o (Haskell)
%o import Data.List (elemIndices)
%o a125217 n = a125217_list !! (n-1)
%o a125217_list = map (+ 1) $ elemIndices 1 a125203_list
%o -- _Reinhard Zumkeller_, Jan 02 2013
%K nonn
%O 1,1
%A _Reinhard Zumkeller_, Nov 24 2006
|
