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A168004 Numbers n with property that first digit of 8*n = last digit of n. 2
21, 32, 43, 54, 65, 76, 86, 97, 108, 119, 131, 141, 151, 161, 171, 181, 191, 201, 211, 221, 231, 241, 252, 262, 272, 282, 292, 302, 312, 322, 332, 342, 352, 362, 372, 383, 393, 403, 413, 423, 433, 443, 453, 463, 473, 483, 493, 504, 514, 524, 534, 544, 554 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

For 1 <= t <= 9, n = 10*s+t is in the sequence iff for some d>=1, t*(10^d-8)/80 <= s <= t*(10^d-8)/10 + (10^d-1)/80.  For each d >= 3, there are 10^d/8 such m. - Robert Israel, Jul 04 2016

a(n) - a(n-1) can be 1 : 8*624 = 4992 and 8*625 = 5000. - Altug Alkan, Jul 04 2016

EXAMPLE

8*21=168, 8*32=256, 8*43=344, 8*54=432, etc.

MAPLE

select(n -> floor(8*n/10^ilog10(8*n))=n mod 10, [$1..554]); # Robert Israel, Jul 04 2016

MATHEMATICA

Reap[Do[If[IntegerDigits[n][[ -1]]==IntegerDigits[8*n][[1]], Sow[n]], {n, 1000}]][[2, 1]]

Select[Range[800], Last[IntegerDigits[#]]==First[IntegerDigits[8#]]&] (* Harvey P. Dale, Nov 03 2013 *)

CROSSREFS

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

Sequence in context: A054282 A095994 A168001 * A118866 A168005 A118535

Adjacent sequences:  A168001 A168002 A168003 * A168005 A168006 A168007

KEYWORD

base,nonn

AUTHOR

Zak Seidov, Nov 16 2009

STATUS

approved

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Last modified August 20 10:41 EDT 2019. Contains 326150 sequences. (Running on oeis4.)