login
a(1)=1, a(n)= least odd triangular number which is a proper multiple of a(n-1) with a multiplier different from the ones used earlier.
0

%I #4 Dec 05 2013 19:56:33

%S 1,3,15,105,2415,26565,1567335,2785154295,6918860803558935,

%T 24055444284403886996443725,

%U 332872543972802173225078010738842685950725,571002075998998180604720399522520480910497598676930064638396594614026468525

%N a(1)=1, a(n)= least odd triangular number which is a proper multiple of a(n-1) with a multiplier different from the ones used earlier.

%e a(2)/a(1) = 3, a(3)/a(2) = 5, a(4)/a(3) = 7, a(5)/a(4) = 23.

%e a(4) = 105 and not 45, = 3*15.

%Y Cf. A088108.

%K nonn

%O 1,2

%A _Amarnath Murthy_, Sep 24 2003

%E More terms from _David Wasserman_, Jul 20 2005