A283682 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).

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, 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, 2, 3, 4, 2, 2, 4, 3, 2, 3, 2, 2, 3, 3, 2, 4, 3, 2, 3, 4, 2, 3, 3

Offset

1,5

Comments

Any positive integer appears infinitely many times.

Links

Ivan Neretin, Table of n, a(n) for n = 1..26796

Example

The sequence begins: 0, 1, 1, 1, 2, 1, 1, 2, 2, 1, ...
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:
0 1 1 1 2 1...
1 2 2 2 3...
1 2 2 2...
1 2 2...
2 3...
1...
...

Mathematica

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

Crossrefs

Cf. A283681, A283683.

Sequence in context: A002636 A353656 A196062 * A087974 A008679 A029435

Adjacent sequences: A283679 A283680 A283681 * A283683 A283684 A283685

Keyword

nonn,tabl

Author

Ivan Neretin, Mar 14 2017

Status

approved