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A052218
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Numbers whose sum of digits is 4.
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36
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4, 13, 22, 31, 40, 103, 112, 121, 130, 202, 211, 220, 301, 310, 400, 1003, 1012, 1021, 1030, 1102, 1111, 1120, 1201, 1210, 1300, 2002, 2011, 2020, 2101, 2110, 2200, 3001, 3010, 3100, 4000, 10003, 10012, 10021, 10030, 10102, 10111, 10120, 10201, 10210, 10300
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OFFSET
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1,1
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COMMENTS
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LINKS
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MATHEMATICA
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Select[Range[10^5], Total[IntegerDigits[#]] == 4 &] (* Vincenzo Librandi, Mar 07 2013 *)
Union[Flatten[Table[FromDigits /@ Permutations[PadRight[s, 11]], {s, IntegerPartitions[4]}]]] (* T. D. Noe, Mar 08 2013 *)
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PROG
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(Haskell)
a052218 n = a052218_list !! (n-1)
a052218_list = filter ((== 4) . a007953) [0..]
(PARI) isok(n) = sumdigits(n) == 4; \\ Michel Marcus, Dec 28 2015
(Python)
from itertools import count, islice
def agen(): yield from (10**i + 10**j + 10**k + 10**m for i in count(0) for j in range(i+1) for k in range(j+1) for m in range(k+1))
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CROSSREFS
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Cf. A011557 (1), A052216 (2), A052217 (3), 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), A235228 (18), A166459 (19), A235229 (20).
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KEYWORD
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nonn,base,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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