|
%I #19 Sep 08 2022 08:44:37
%S 19,218,327,436,545,654,763,872,981,1090,1199,12108,13117,14126,15135,
%T 16144,17153,18162,19171,20180,21189,22198,23207,24216,25225,26234,
%U 27243,28252,29261,30270,31279,32288,33297,34306,35315,36324,37333,38342,39351
%N a(n) is the concatenation of n and 9n.
%H Vincenzo Librandi, <a href="/A009474/b009474.txt">Table of n, a(n) for n = 1..1000</a>
%t nxt[n_]:=Module[{idn=IntegerDigits[n], idn9=IntegerDigits[9n]}, FromDigits[Join[idn, idn9]]]; Array[nxt, 100] (* _Vincenzo Librandi_, Feb 04 2014 *)
%o (Magma) [Seqint(Intseq(9*n) cat Intseq(n)): n in [1..50]]; // _Vincenzo Librandi_, Feb 04 2014
%Y Cf. concatenation of n and k*n: A020338 (k=1), A019550 (k=2), A019551 (k=3), A019552 (k=4), A019553 (k=5), A009440 (k=6), A009441 (k=7), A009470 (k=8), this sequence (k=9).
%K nonn,base,less,easy
%O 1,1
%A _David W. Wilson_
|
