This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
a052217 n = a052217_list !! (n-1) a052217_list = filter ((== 3) . a007953) [0..] -- Reinhard Zumkeller, Jul 17 2014
[n: n in [1..100101] | &+Intseq(n) eq 3 ]; // Vincenzo Librandi, Mar 07 2013
Union[FromDigits/@Select[Flatten[Table[Tuples[Range[0,3],n],{n,6}],1],Total[#]==3&]] (* Harvey P. Dale, Oct 20 2012 *)
Select[Range[10^6], Total[IntegerDigits[#]] == 3 &] (* Vincenzo Librandi, Mar 07 2013 *)
Union[Flatten[Table[FromDigits /@ Permutations[PadRight[s, 18]], {s, IntegerPartitions[3]}]]] (* T. D. Noe, Mar 08 2013 *)
isok(n) = sumdigits(n) == 3; \\ Michel Marcus, Dec 28 2015
apply( {A052217_row(n,s,t=-1)=vector(n*(n+1)\2,k,t++>s&&t=!s++;10^(n-1)+10^s+10^t)}, [1..5]) \\ M. F. Hasler, Feb 19 2020
from itertools import count, islice def agen(): yield from (10**i + 10**j + 10**k for i in count(0) for j in range(i+1) for k in range(j+1)) print(list(islice(agen(), 40))) # Michael S. Branicky, May 14 2022
from math import comb, isqrt from sympy import integer_nthroot def A052217(n): return 10**((m:=integer_nthroot(6*n,3)[0])-(a:=n<=comb(m+2,3)))+10**((k:=isqrt(b:=(c:=n-comb(m-a+2,3))<<1))-((b<<2)<=(k<<2)*(k+1)+1))+10**(c-1-comb(k+(b>k*(k+1)),2)) # Chai Wah Wu, Dec 11 2024
a(n) = my(r,s=sqrtint((n-1)<<1,&r), x=s+(r>s), y=if(r>s,r-s,r+s)>>1); 10^x + 10^y; \\ Kevin Ryde, Jul 17 2025
from itertools import product
def agen():
digits = 1
while True:
for i in range(digits-2): yield int("1"+"0"*(digits-3-i)+"1"+"0"*i+"0")
yield int("2"+"0"*(digits-1))
digits += 1
g = agen()
print([next(g) for i in range(32)]) # Michael S. Branicky, Feb 20 2021
4 is an element of the sequence, since 4 is a multiple of 4 the sum of whose digits is 4; 220 is an element of the sequence, since 220 = 4*55 and 2 + 2+ 0 = 4.
Select[4Range[120000],Total[IntegerDigits[#]]==4&] (* Harvey P. Dale, May 07 2011 *)
SumDE(x,y)= { local(s); s=0; while (x>9 && sHarry J. Smith, Sep 05 2009
t={}; Do[i=2; While[Total[IntegerDigits[i]]!=n,i=i+2]; AppendTo[t,i],{n,48}]; t (* Jayanta Basu, May 18 2013 *)
a(n) = {my(k = 2); while(sumdigits(k) != n, k+=2); k;} \\ Michel Marcus, Mar 18 2016
60 is a member of the sequence since 60 / 6 = 10 and 6 + 0 = 6; 114 is also an element since 114 is divisible by 6 and 1 + 1+ 4 = 6.
: var stk: stack; end; minarg := 0; maxarg := 900; n := 6; for k := minarg to maxarg do m := k*n; s := itoa(m); for j := 0 to length(s) - 1 do stack_push(stk,atoi(s[j..j])); end; if sum(stack2array(stk)) = n then write(m," "); end; end;.
Select[ Range[ 6, 4200, 6 ], Plus @@ IntegerDigits[ # ] == 6 & ]
133 = 19*7 and 1+3+3 = 7, so 133 is a term of this sequence.
: var stk: stack; end; minarg := 0; maxarg := 5000; n := 7; for k := minarg to maxarg do m := k*n; s := itoa(m); for j := 0 to length(s) - 1 do stack_push(stk,atoi(s[j..j])); end; if sum(stack2array(stk)) = n then write(m," "); end; end;.
Select[Range[7, 25000, 7], Plus @@ IntegerDigits[ # ] == 7 &]
forstep(m=0, 70000, 7, if(vecsum(digits(m))==7, print1(m, ", "))) \\ Harry J. Smith, Aug 20 2009
Select[5*Range[5000],Total[IntegerDigits[#]]==5&] (* Harvey P. Dale, Nov 08 2017 *)
t={}; Do[i=5; While[Total[IntegerDigits[i]]!=n,i=i+5]; AppendTo[t,i],{n,46}]; t (* Jayanta Basu, May 19 2013 *)
With[{f=5*Range[200000]},Flatten[Table[Select[f,Total[IntegerDigits[#]] == n&,1],{n,50}]]] (* Harvey P. Dale, Dec 31 2013 *)
A069534(n)=(((n+4)%9+1)*10^((n+4)\9)-5)*10^(n<5) \\ M. F. Hasler, Sep 16 2016
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