A359124 - OEIS

A359124

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

%I #12 Dec 20 2022 18:47:45

%S 2,13,124,1235,12346,123457,1234568,12345679,123456790,12345678911,

%T 1234567891012,123456789101113,12345678910111214,1234567891011121315,

%U 123456789101112131416,12345678910111213141517,1234567891011121314151618,123456789101112131415161719,12345678910111213141516171820

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

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

%C Studied in A069048.

%t Table[FromDigits[Flatten[IntegerDigits/@Range[n]]]+1,{n,20}] (* _Harvey P. Dale_, Dec 20 2022 *)

%o (Python)

%o def a(n): return int("".join(map(str, range(1, n+1)))) + 1

%o print([a(n) for n in range(1, 20)]) # _Michael S. Branicky_, Dec 20 2022

%Y Cf. A007908, A069048, A359125.

%K nonn,base

%O 1,1

%A _N. J. A. Sloane_, Dec 20 2022