A235228 - OEIS

%I #15 Sep 08 2022 08:46:06

%S 99,189,198,279,288,297,369,378,387,396,459,468,477,486,495,549,558,

%T 567,576,585,594,639,648,657,666,675,684,693,729,738,747,756,765,774,

%U 783,792,819,828,837,846,855,864,873,882,891,909,918,927,936,945,954,963

%N Numbers whose sum of digits is 18.

%C A007953(a(n)) = 18; number of repdigits = #{99,666,333333,222222222,1^18} = A242627(18) = 5. - _Reinhard Zumkeller_, Jul 17 2014

%H Vincenzo Librandi, <a href="/A235228/b235228.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = 9*A279769(n). - _M. F. Hasler_, Dec 23 2016

%t Select[Range[1000], Total[IntegerDigits[#]] == 18 &]

%o (Magma) [n: n in [1..1000] | &+Intseq(n) eq 18];

%o (Haskell)

%o a235228 n = a235228_list !! (n-1)

%o a235228_list = filter ((== 18) . a007953) [0..]

%o -- _Reinhard Zumkeller_, Jul 17 2014

%Y Cf. A052217 - A052224, A061423, A143164, A166311, A166370, A166459.

%Y Cf. A011557 (1), A052216 (2), A052217 (3), A052218 (4), A052219 (5), A052220 (6), A052221 (7), A052222 (8), A052223 (9), A052224 (10), A166311 (11), A235151 (12), A143164 (13), A235225(14), A235226 (15), A235227 (16), A166370 (17), A166459 (19), A235229 (20).

%Y Cf. A242614, A242627.

%K nonn,base,easy

%O 1,1

%A _Vincenzo Librandi_, Jan 05 2014