A082247 Multiples of 7 that are concatenation of 7 consecutive natural numbers.

3456789, 13141516171819, 20212223242526, 27282930313233, 34353637383940, 41424344454647, 48495051525354, 55565758596061, 62636465666768, 69707172737475, 76777879808182, 83848586878889, 90919293949596, 102103104105106107108, 109110111112113114115

Offset: 1

Author

Amarnath Murthy, Apr 11 2003

Keywords

• base
• easy
• nonn

Comments

From 2nd terms onwards it is observed that if a(r) ends in k then a(r+1) begins with k+1. This is true up to the term 90919293949596. (Why?)

Links

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

Crossrefs

Cf. A082242, A082243, A082248.

Programs

Mathematica

Select[FromDigits[Flatten[IntegerDigits[#]]]&/@Partition[Range[100],7,1],Divisible[ #,7]&] (* Harvey P. Dale, May 18 2021 *)