A234964 Numbers of the form 123...n - (n+1)

9, 119, 1229, 12339, 123449, 1234559, 12345669, 123456779, 12345678899, 1234567890999, 123456789101099, 12345678910111199, 1234567891011121299, 123456789101112131399, 12345678910111213141499, 1234567891011121314151599, 123456789101112131415161699

Offset

2,1

Links

Table of n, a(n) for n=2..18.

Example

a(3) = 123 - 4 = 119.
a(4) = 1234 - 5 = 1229.
a(5) = 12345 - 6 = 12339.
etc.

Prog

(Python)
def Concatenate(x):
..num = ''
..for n in range(1, x+1):
....num += str(n)
..return int(num)
{print(Concatenate(x)-(x+1)) for x in range(1, 50)}

Crossrefs

Cf. A007908.

Sequence in context: A340236 A087984 A197544 * A210046 A130652 A054051

Adjacent sequences: A234961 A234962 A234963 * A234965 A234966 A234967

Keyword

nonn,base

Author

Derek Orr, Jan 02 2014

Status

approved