A322426 Array read by downwards antidiagonals: A(n, k) is the k-th term of a "Look to the left" sequence starting with 1,2,...,n (see A293630).

1, 2, 1, 1, 2, 1, 1, 3, 2, 1, 1, 1, 3, 2, 1, 2, 2, 4, 3, 2, 1, 1, 1, 1, 4, 3, 2, 1, 1, 2, 2, 5, 4, 3, 2, 1, 2, 1, 3, 1, 5, 4, 3, 2, 1, 1, 2, 1, 2, 6, 5, 4, 3, 2, 1, 1, 1, 2, 3, 1, 6, 5, 4, 3, 2, 1, 1, 2, 3, 4, 2, 7, 6, 5, 4, 3, 2, 1, 2, 3, 1, 1, 3, 1, 7, 6, 5

Offset

2,2

Links

Iain Fox, Antidiagonals n = 1..141 of array, flattened

Formula

If k <= n, A(n, k) = k.

Example

| n\k |  1   2   3   4   5   6   7   8   9  10  11  12  13  ...
|-----|-----------------------------------------------------------
|  2  |  1,  2,  1,  1,  1,  2,  1,  1,  2,  1,  1,  1,  2, ...
|  3  |  1,  2,  3,  1,  2,  1,  2,  1,  2,  1,  2,  3,  1, ...
|  4  |  1,  2,  3,  4,  1,  2,  3,  1,  2,  3,  1,  2,  3, ...
|  5  |  1,  2,  3,  4,  5,  1,  2,  3,  4,  1,  2,  3,  4, ...
|  6  |  1,  2,  3,  4,  5,  6,  1,  2,  3,  4,  5,  1,  2, ...
|  7  |  1,  2,  3,  4,  5,  6,  7,  1,  2,  3,  4,  5,  6, ...
|  8  |  1,  2,  3,  4,  5,  6,  7,  8,  1,  2,  3,  4,  5, ...
| ... |

Prog

(PARI) row(n, k) = my(v=vector(n, i, i), w); while(#v<k, w=vector(#v-1, i, v[i]); for(y=1, v[#v], v=concat(v, w))); vector(k, i, v[i])
first(n, k) = my(v, m=matrix(0, k)); for(x=1, n, v=row(x+1, k); m=concat(m, v)); m

Crossrefs

n-th row: A293630 (n=2), A322423 (n=3), A322424 (n=4), A322425 (n=5).

Sequence in context: A262928 A228429 A108316 * A335438 A145574 A182579

Adjacent sequences: A322423 A322424 A322425 * A322427 A322428 A322429

Keyword

nonn,tabl,look

Author

Iain Fox, Dec 07 2018

Status

approved