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.
a037268 n = a037268_list !! (n-1)
a037268_list = filter ((== 1) . a168046) $
takeWhile (<= 999999999) a214959_list
-- Reinhard Zumkeller, Aug 02 2012
A037268 := proc(n) option remember: local d,k: if(n=1)then return 1: fi: for k from procname(n-1)+1 do d:=convert(k,base,10): if(not member(0,d) and add(1/d[j],j=1..nops(d))=1)then return k: fi: od: end: seq(A037268(n),n=1..50); # Nathaniel Johnston, May 28 2011
Select[Range[10000],Total[1/(IntegerDigits[#]/.(0->1))]==1&] (* Harvey P. Dale, Jul 23 2025 *)
lista(nn) = {for (n=1, nn, d = digits(n); if (vecmin(d) && (sum(k=1, #d, 1/d[k])==1), print1(n, ", ")););} \\ Michel Marcus, Jul 06 2015
from fractions import Fraction def ok(n): sn = str(n) return False if '0' in sn else sum(Fraction(1, int(d)) for d in sn) == 1 def aupto(limit): return [m for m in range(1, limit+1) if ok(m)] print(aupto(8824)) # Michael S. Branicky, Jan 22 2021
import Data.Ratio ((%), numerator)
a214949 = f 0 where
f y 0 = numerator y
f y x = f (y + if d == 0 then 0 else 1 % d) x'
where (x',d) = divMod x 10
nsr[n_] := Numerator[Total[1/Select[IntegerDigits[n], # > 0 &]]]; nsr /@ Range[0, 79] (* Jayanta Basu, Jul 13 2013 *)
a(n) = my(d=digits(n)); numerator(sum(k=1, #d, if (d[k], 1/d[k]))); \\ Michel Marcus, Jan 26 2022
a214958 n = a214958_list !! (n-1) a214958_list = [x | x <- [0..], a214949 x == 1]
nsrQ[n_] := Numerator[Total[1/Select[IntegerDigits[n], # > 0 &]]] == 1; Select[Range[884], nsrQ] (* Jayanta Basu, Jul 13 2013 *)
1/3 + 1/4 + 1/6 + 1/8 + 1/8 = 1/1, so 34688 is in the sequence.
a045910 n = a045910_list !! (n-1)
a045910_list = [x | x <- takeWhile (<= 999999999) $ a009994_list,
a214949 x == 1]
-- Reinhard Zumkeller, Aug 02 2012
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