A112131 Concatenate the consecutive increasing numbers starting with Harshad(n) and ending with Harshad(n+1).

12, 23, 34, 45, 56, 67, 78, 89, 910, 101112, 12131415161718, 181920, 2021, 21222324, 24252627, 27282930, 30313233343536, 3637383940, 404142, 42434445, 45464748, 484950, 5051525354, 54555657585960, 60616263, 6364656667686970, 707172

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

a(11)=12131415161718 because the 11th Harshad is 12 and the 12th
is 18 and we concatenate those with the increasing numbers between.

Mathematica

FromDigits[Flatten[IntegerDigits/@Range[#[[1]], #[[2]]]]]&/@Partition[ Select[ Range[80], Divisible[#, Total[IntegerDigits[#]]]&], 2, 1] (* Harvey P. Dale, Feb 10 2019 *)

Crossrefs

Cf. A005349.

Sequence in context: A035333 A001704 A127421 * A233032 A088997 A049852

Adjacent sequences: A112128 A112129 A112130 * A112132 A112133 A112134

Keyword

base,easy,nonn

Author

Jason Earls, Aug 27 2005

Status

approved