A167994 Numbers k with the property that the first digit of 2*k is the last digit of k.

12, 24, 25, 37, 49, 51, 61, 71, 81, 91, 102, 112, 122, 132, 142, 153, 163, 173, 183, 193, 204, 214, 224, 234, 244, 255, 265, 275, 285, 295, 306, 316, 326, 336, 346, 357, 367, 377, 387, 397, 408, 418, 428, 438, 448, 459, 469, 479, 489, 499, 501, 511, 521, 531

Offset

1,1

Links

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

Example

2*12=24, 2*24=48, 2*25=50, 2*37=74.

Mathematica

Select[Range[600], Mod[#, 10]==First[IntegerDigits[2#]]&] (* Harvey P. Dale, May 27 2014 *)

Crossrefs

Sequence in context: A297276 A095780 A119588 * A065303 A239673 A372548

Adjacent sequences: A167991 A167992 A167993 * A167995 A167996 A167997

Keyword

base,nonn

Author

Zak Seidov, Nov 16 2009

Status

approved