%I #22 Mar 29 2022 11:00:26
%S 9,18,27,36,45,54,63,72,81,90,99,117,126,135,144,153,162,171,180,189,
%T 207,216,225,234,243,252,261,270,279,297,315,324,333,342,351,360,369,
%U 387,405,414,423,432,441,450,459,477,495,513,522,531,540
%N a(n+1) = a(n) + sum of its digits, with a(1) = 9.
%D D. R. Kaprekar, Puzzles of the Self-Numbers. 311 Devlali Camp, Devlali, India, 1959.
%D D. R. Kaprekar, The Mathematics of the New Self Numbers, Privately printed, 311 Devlali Camp, Devlali, India, 1963.
%H Reinhard Zumkeller, <a href="/A016096/b016096.txt">Table of n, a(n) for n = 1..10000</a>
%H D. R. Kaprekar, <a href="/A003052/a003052_2.pdf">The Mathematics of the New Self Numbers</a> [annotated and scanned]
%H <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a>
%F a(n) = A062028(a(n-1)) for n > 1. - _Reinhard Zumkeller_, Oct 14 2013
%o (Haskell)
%o a016096 n = a016096_list !! (n-1)
%o a016096_list = iterate a062028 9 -- _Reinhard Zumkeller_, Oct 14 2013
%o (Python)
%o from itertools import islice
%o def A016096_gen(): # generator of terms
%o a = 9
%o while True:
%o yield a
%o a += sum(int(d) for d in str(a))
%o A016096_list = list(islice(A016096_gen(),20)) # _Chai Wah Wu_, Mar 29 2022
%Y Cf. A004207, A016052, A007618, A006507.
%K nonn,base
%O 1,1
%A _Robert G. Wilson v_