A062181 Harmonic mean of digits is 3.

3, 26, 33, 62, 236, 244, 263, 326, 333, 362, 424, 442, 623, 632, 1999, 2266, 2336, 2344, 2363, 2434, 2443, 2626, 2633, 2662, 3236, 3244, 3263, 3326, 3333, 3362, 3424, 3442, 3623, 3632, 4234, 4243, 4324, 4342, 4423, 4432, 6226, 6233, 6262, 6323, 6332

Offset

1,1

Links

Table of n, a(n) for n=1..45.

Eric Weisstein's World of Mathematics, Harmonic Mean.

Wikipedia, Harmonic mean.

Mathematica

Do[ h = IntegerDigits[n]; If[ Sort[h][[1]] != 0 && Length[h]/Apply[Plus, 1/h] == 3, Print[n]], {n, 1, 10^4}]

Prog

(Python)
from fractions import Fraction
def hm(n):
  s = str(n)
  return None if '0' in s else len(s)/sum(Fraction(1, int(d)) for d in s)
def aupto(limit): return [m for m in range(limit+1) if hm(m) == 3]
print(aupto(6332)) # Michael S. Branicky, Mar 26 2021

Crossrefs

Cf. A062179-A062185, A061383-A061388, A061423-A061425.

Sequence in context: A326610 A221616 A321222 * A058993 A358352 A083109

Adjacent sequences: A062178 A062179 A062180 * A062182 A062183 A062184

Keyword

base,easy,nonn

Author

Vladeta Jovovic, Jun 12 2001

Extensions

More terms from Henry Bottomley, Jul 25 2001

Status

approved