A283682 - OEIS

%I #6 Mar 16 2017 22:54:03

%S 0,1,1,1,2,1,1,2,2,1,2,2,2,2,2,1,3,2,2,3,1,1,2,3,2,3,2,1,2,2,2,3,3,2,

%T 2,2,2,3,2,2,4,2,2,3,2,1,3,3,2,3,3,2,3,3,1,2,2,3,3,3,2,3,3,3,2,2,2,3,

%U 2,3,4,2,2,4,3,2,3,2,2,3,3,2,4,3,2,3,4,2,3,3

%N Unique sequence with a(1)=0, a(2)=1, representing an array T(i,j) read by antidiagonals in which T(i,j) = a(i) + a(j).

%C Any positive integer appears infinitely many times.

%H Ivan Neretin, <a href="/A283682/b283682.txt">Table of n, a(n) for n = 1..26796</a>

%e The sequence begins: 0, 1, 1, 1, 2, 1, 1, 2, 2, 1, ...

%e It represents a rectangular array read by downward antidiagonals. The first row of the array is this sequence itself; so is the first column. Every term in the array is the sum of the initial terms of its row and column:

%e 0 1 1 1 2 1...

%e 1 2 2 2 3...

%e 1 2 2 2...

%e 1 2 2...

%e 2 3...

%e 1...

%e ...

%t Nest[Flatten@Table[#[[n - i]] + #[[i]], {n, Length[#] + 1}, {i, n - 1}] &, {0, 1}, 4]

%Y Cf. A283681, A283683.

%K nonn,tabl

%O 1,5

%A _Ivan Neretin_, Mar 14 2017