

A125886


a(1) = 1, a(n) = smallest positive number b not among a(1)..a(n1) such that the last digit of b = the first digit of a(n1).


3



1, 11, 21, 12, 31, 13, 41, 14, 51, 15, 61, 16, 71, 17, 81, 18, 91, 19, 101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 201, 22, 32, 23, 42, 24, 52, 25, 62, 26, 72, 27, 82, 28, 92, 29, 102, 211, 112, 221, 122, 231, 132, 241, 142, 251, 152, 261, 162, 271, 172, 281, 182
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

A dyslexic person might have trouble distinguishing this sequence from A125887!
A010879(a(n+1)) = A000030(a(n)).  Reinhard Zumkeller, Aug 10 2014


LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
Hans Havermann, Graph of first 10000 terms


MATHEMATICA

s={1}; fi=1; Do[Do[id=IntegerDigits[i]; la=id[[ 1]]; If[fi==la&&FreeQ[s, i], AppendTo[s, i]; fi=id[[1]]; Break[]], {i, 11, 10^5}], {999}]; s


PROG

(Haskell)
import Data.List (delete)
a125886 n = a125886_list !! (n1)
a125886_list = 1 : f 1 [10..] where
f u vs = g vs where
g (w:ws) = if a010879 w == iu then w : f w (delete w vs) else g ws
iu = a000030 u
 Reinhard Zumkeller, Aug 10 2014


CROSSREFS

Cf. A125887.
Cf. A000030, A010879.
Sequence in context: A061384 A071154 A071161 * A067574 A299400 A300296
Adjacent sequences: A125883 A125884 A125885 * A125887 A125888 A125889


KEYWORD

base,nonn,look,hear


AUTHOR

Zak Seidov, Dec 13 2006


STATUS

approved



