A236903 Row sums of an analog of Pascal's triangle resulting from replacing addition with concatenation in the construction rule.

1, 2, 13, 224, 113335, 2222244446, 11111333333333555557, 22222222222222444444444444446666668, 1111111111111133333333333333333333333333335555555555555555555577777779

Offset

0,2

Comments

Number of digits of a(n) is A001405(n).

a(2n) begins with exactly A000108(n) 1's. - Vladimir Shevelev, Feb 07 2014

Links

Alois P. Heinz, Table of n, a(n) for n = 0..12

Example

Triangle begins
.                      1
.
.                 1         1
.
.            1        11         1
.
.       1        111       111        1
.
.  1       1111     111111     1111        1

Maple

a:= n-> add((10^binomial(n, k)-1)/9, k=0..n):
seq(a(n), n=0..8);  # Alois P. Heinz, Feb 01 2014

Crossrefs

Cf. A001405, A007318.

Sequence in context: A069569 A255882 A015196 * A277452 A268703 A369799

Adjacent sequences: A236900 A236901 A236902 * A236904 A236905 A236906

Keyword

nonn,base

Author

Vladimir Shevelev, Feb 01 2014

Status

approved