A084854 Triangular array, read by rows: T(n,k) = concatenated decimal representations of n and k, 1<=k<=n.

11, 21, 22, 31, 32, 33, 41, 42, 43, 44, 51, 52, 53, 54, 55, 61, 62, 63, 64, 65, 66, 71, 72, 73, 74, 75, 76, 77, 81, 82, 83, 84, 85, 86, 87, 88, 91, 92, 93, 94, 95, 96, 97, 98, 99, 101, 102, 103, 104, 105, 106, 107, 108, 109, 1010, 111, 112, 113, 114, 115, 116, 117, 118, 119, 1110, 1111

Offset: 1

Author

Reinhard Zumkeller, Jun 09 2003

Keywords

• nonn
• base
• tabl

Links

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

Crossrefs

Cf. A017281, A020338, A055642, A066686, A067574, A084855.

Programs

Python

def T(n, k): return int(str(n) + str(k))
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

Formula

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

T(n, 1) = A017281(n); T(n, n) = A020338(n).