A168005 Numbers n with property that first digit of 9*n = last digit of n.

21, 32, 43, 54, 65, 76, 87, 98, 109, 121, 131, 141, 151, 161, 171, 181, 191, 201, 211, 221, 232, 242, 252, 262, 272, 282, 292, 302, 312, 322, 332, 343, 353, 363, 373, 383, 393, 403, 413, 423, 433, 443, 454, 464, 474, 484, 494, 504, 514, 524, 534, 544, 554

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Example

9*21=189, 9*32=288, 9*43=387, 9*54=486, etc.

Mathematica

Reap[Do[If[IntegerDigits[n][[ -1]]==IntegerDigits[9*n][[1]], Sow[n]], {n, 1000}]][[2, 1]]
Select[Range[100], Last[IntegerDigits[#]] == First[IntegerDigits[9 #]] &] (* G. C. Greubel, Jul 03 2016 *)

Crossrefs

Cf. A167994, A167996, A167997, A167998, A168000, A168001, A168004.

Sequence in context: A380225 A168004 A118866 * A118535 A127423 A319477

Adjacent sequences: A168002 A168003 A168004 * A168006 A168007 A168008

Keyword

base,nonn

Author

Zak Seidov, Nov 16 2009

Status

approved