A260004 - OEIS

%I #31 Jan 11 2020 15:57:47

%S 1,8,19,27,74,185,440,1015,2294,5109,10228,11252,24563,53234,114673,

%T 245744,524271,1114094,2359277,4980716,10485739,22020074,46137321,

%U 88080360,96468968,201326567,419430374,872415205,1811939300,15569256417

%N Values of f(2,x,y) in increasing order, for x>=0, y>0 where f is the Sudan function defined in A260002.

%C This is a subsequence of A260003 since f(2,x,y)= f(1, f(2,x,y-1), f(2,x,y-1)+y).

%C In this list we suppose that y>0. If we take y=0, all the natural numbers would be in the sequence.

%C To evaluate the Sudan function see A260002-A260003.

%e f(2,0,1) = f(1, f(2,0,0), f(2,0,0)+1) = f(1,0,1) = 2^1(0+2)-1-2 = 1;

%e f(2,0,2) = f(1, [f(2,0,1)], [f(2,0,1)+1+1]) = f(1,1,3) = 2^3(1+2)-3-2 = 19;

%Y Cf. A048493 (f(2,n,1)), A260002, A260003, A260005 (f(2,n,2)), A260006.

%K nonn

%O 1,2

%A _Natan Arie Consigli_, Jul 23 2015