A359124 Concatenate the decimal numbers 1,2,3,...,n, then add 1.

2, 13, 124, 1235, 12346, 123457, 1234568, 12345679, 123456790, 12345678911, 1234567891012, 123456789101113, 12345678910111214, 1234567891011121315, 123456789101112131416, 12345678910111213141517, 1234567891011121314151618, 123456789101112131415161719, 12345678910111213141516171820

Offset

1,1

Comments

a(n) = A007908(n)+1.

Studied in A069048.

Links

Table of n, a(n) for n=1..19.

Mathematica

Table[FromDigits[Flatten[IntegerDigits/@Range[n]]]+1, {n, 20}] (* Harvey P. Dale, Dec 20 2022 *)

Prog

(Python)
def a(n): return int("".join(map(str, range(1, n+1)))) + 1
print([a(n) for n in range(1, 20)]) # Michael S. Branicky, Dec 20 2022

Crossrefs

Cf. A007908, A069048, A359125.

Sequence in context: A317196 A192460 A004122 * A086630 A151361 A328008

Adjacent sequences: A359121 A359122 A359123 * A359125 A359126 A359127

Keyword

nonn,base

Author

N. J. A. Sloane, Dec 20 2022

Status

approved