A069861 Numbers n that divide the concatenation of next n numbers.

1, 2, 3, 5, 6, 9, 10, 11, 12, 15, 18, 20, 21, 22, 25, 27, 30, 33, 36, 39, 42, 44, 45, 50, 54, 56, 60, 68, 72, 75, 90, 98, 100, 104, 108, 110, 111, 114, 120, 125, 126, 130, 132, 135, 140, 148, 150, 154, 155, 156, 162, 168, 180, 182, 185, 196, 198, 200, 205, 210, 216

Offset

1,2

Links

Table of n, a(n) for n=1..61.

Example

9 divides 101112131415161718 hence is a member.

Mathematica

f[n_] := Block[{j = 0, k = n + 1}, While[k < 2n + 1, j = ToExpression[ StringJoin[ ToString[j], ToString[k]]]; k++ ]; j]; Select[ Range[300], IntegerQ[ f[ # ] / # ] & ]

Crossrefs

Cf. A069860, A069862.

Sequence in context: A069880 A230044 A329269 * A047449 A162923 A107040

Adjacent sequences: A069858 A069859 A069860 * A069862 A069863 A069864

Keyword

base,nonn

Author

Amarnath Murthy, Apr 18 2002

Extensions

Edited, corrected and extended by Robert G. Wilson v

Status

approved