A052218 Numbers whose sum of digits is 4.

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

Offset: 1

Author

Henry Bottomley, Feb 01 2000

Keywords

• nonn
• base
• easy

Comments

A007953(a(n)) = 4; number of repdigits = #{4,22,1111} = A242627(4) = 3. - Reinhard Zumkeller, Jul 17 2014

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..10000 (terms 1..1001 from Vincenzo Librandi and T. D. Noe, terms 1..201 from Vincenzo Librandi)

Crossrefs

Cf. A007953.

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).

Cf. A242614, A242627.

Programs

Haskell

a052218 n = a052218_list !! (n-1)
a052218_list = filter ((== 4) . a007953) [0..]
-- Reinhard Zumkeller, Jul 17 2014

Magma

[n: n in [1..10300] | &+Intseq(n) eq 4 ]; // Vincenzo Librandi, Mar 07 2013

Mathematica

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 *)

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))
print(list(islice(agen(), 45))) # Michael S. Branicky, May 15 2022

Extensions

Offset changed from Bruno Berselli, Mar 07 2013