A084855 Triangular array, read by rows: T(n,k) = concatenated decimal representations of k and n, 1<=k<=n.

11, 12, 22, 13, 23, 33, 14, 24, 34, 44, 15, 25, 35, 45, 55, 16, 26, 36, 46, 56, 66, 17, 27, 37, 47, 57, 67, 77, 18, 28, 38, 48, 58, 68, 78, 88, 19, 29, 39, 49, 59, 69, 79, 89, 99, 110, 210, 310, 410, 510, 610, 710, 810, 910, 1010, 111, 211, 311, 411, 511, 611, 711, 811, 911, 1011, 1111

Offset

1,1

Links

Indranil Ghosh, Rows 1..100 of triangle, flattened

Formula

T(n, k) = k*10^A055642(n) + n.

T(n, n) = A020338(n).

Prog

(Python)
def T(n, k): return int(str(k) + str(n))
def auptorow(maxrow):
    return [T(n, k) for n in range(1, maxrow+1) for k in range(1, n+1)]
print(auptorow(11)) # Michael S. Branicky, Nov 21 2021

Crossrefs

Cf. A020338, A055642, A066686, A067574, A084854, A349520.

Sequence in context: A240763 A231871 A192287 * A367612 A367340 A101233

Adjacent sequences: A084852 A084853 A084854 * A084856 A084857 A084858

Keyword

nonn,base,tabl

Author

Reinhard Zumkeller, Jun 09 2003

Status

approved