A067574 Array T(i,j) read by ascending antidiagonals, where T(i,j) is the concatenation of i and j (1<=i, 1<=j).

11, 21, 12, 31, 22, 13, 41, 32, 23, 14, 51, 42, 33, 24, 15, 61, 52, 43, 34, 25, 16, 71, 62, 53, 44, 35, 26, 17, 81, 72, 63, 54, 45, 36, 27, 18, 91, 82, 73, 64, 55, 46, 37, 28, 19, 101, 92, 83, 74, 65, 56, 47, 38, 29, 110, 111, 102, 93, 84, 75, 66, 57, 48, 39, 210, 111

Offset

1,1

Comments

The antidiagonals are read in the opposite direction to those in A066686.

Links

Table of n, a(n) for n=1..66.

Formula

T(i, j) = i*10^A055642(i) + j. - Michael S. Branicky, Nov 21 2021

Example

The array begins
11 12 13 14 15 16 17 18 19 110 ...
21 22 23 24 25 26 27 28 29 210 ...
31 32 33 34 35 36 37 38 39 310 ...
41 42 43 44 45 46 47 48 49 410 ...

Mathematica

a = {}; Do[ a = Append[a, ToExpression[ StringJoin[ ToString[i - j], ToString[j]]]], {i, 2, 13}, {j, 1, i - 1} ]; a

Prog

(Python)
def T(i, j): return int(str(i) + str(j))
def auptodiag(maxd):
    return [T(d+1-j, j) for d in range(1, maxd+1) for j in range(1, d+1)]
print(auptodiag(12)) # Michael S. Branicky, Nov 21 2021

Crossrefs

Cf. A055642, A066686, A084854.

Sequence in context: A367609 A360470 A125886 * A365705 A299400 A300296

Adjacent sequences: A067571 A067572 A067573 * A067575 A067576 A067577

Keyword

base,easy,nonn,tabl

Author

Robert G. Wilson v, Jan 30 2002

Status

approved