login
A062182
Harmonic mean of digits is 4.
1
4, 36, 44, 63, 288, 346, 364, 436, 444, 463, 634, 643, 828, 882, 2488, 2666, 2848, 2884, 3366, 3446, 3464, 3636, 3644, 3663, 4288, 4346, 4364, 4436, 4444, 4463, 4634, 4643, 4828, 4882, 6266, 6336, 6344, 6363, 6434, 6443, 6626, 6633, 6662, 8248, 8284
OFFSET
1,1
LINKS
MAPLE
filter:= proc(n) local L;
L:= convert(n, base, 10);
if has(L, 0) then return false fi;
nops(L)/add(1/i, i=L)=4
end proc:
select(filter, [$1..10^4]); # Robert Israel, Aug 20 2018
MATHEMATICA
Do[ h = IntegerDigits[n]; If[ Sort[h][[1]] != 0 && Length[h]/Apply[Plus, 1/h] == 4, Print[n]], {n, 1, 10^5}]
hm4Q[n_]:=DigitCount[n, 10, 0]==0&&HarmonicMean[IntegerDigits[n]]==4; Select[Range[9000], hm4Q] (* Harvey P. Dale, Mar 23 2011 *)
KEYWORD
base,easy,nonn
AUTHOR
Vladeta Jovovic, Jun 12 2001
EXTENSIONS
More terms from Henry Bottomley, Jul 25 2001
STATUS
approved