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A009474
a(n) is the concatenation of n and 9n.
10
19, 218, 327, 436, 545, 654, 763, 872, 981, 1090, 1199, 12108, 13117, 14126, 15135, 16144, 17153, 18162, 19171, 20180, 21189, 22198, 23207, 24216, 25225, 26234, 27243, 28252, 29261, 30270, 31279, 32288, 33297, 34306, 35315, 36324, 37333, 38342, 39351
OFFSET
1,1
LINKS
MATHEMATICA
nxt[n_]:=Module[{idn=IntegerDigits[n], idn9=IntegerDigits[9n]}, FromDigits[Join[idn, idn9]]]; Array[nxt, 100] (* Vincenzo Librandi, Feb 04 2014 *)
PROG
(Magma) [Seqint(Intseq(9*n) cat Intseq(n)): n in [1..50]]; // Vincenzo Librandi, Feb 04 2014
CROSSREFS
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).
Sequence in context: A115854 A220978 A367980 * A045492 A026892 A142487
KEYWORD
nonn,base,less,easy
STATUS
approved