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Search: id:A062179
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| A062179 |
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Harmonic mean of digits is an integer. |
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+0
8
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| 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 26, 33, 36, 44, 55, 62, 63, 66, 77, 88, 99, 111, 136, 144, 163, 222, 236, 244, 263, 288, 316, 326, 333, 346, 361, 362, 364, 414, 424, 436, 441, 442, 444, 463, 488, 555, 613, 623, 631, 632, 634, 643, 666, 777, 828, 848, 882, 884
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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1236 is a term as the harmonic mean is 4/(1+1/2+1/3+1/6) = 2.
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MATHEMATICA
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Do[ h = IntegerDigits[n]; If[ Sort[h] [[1]] != 0 && IntegerQ[ Length[h] / Apply[ Plus, 1/h] ], Print[n]], {n, 1, 10^4} ] Note that the number of entries <= 10^n are 9, 22, 61, 198, 927, 4738, 24620, 130093,
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CROSSREFS
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Cf. A062180-A062185, A061383-A061388, A061423-A061425.
Sequence in context: A102235 A107272 A039228 this_sequence A122875 A080716 A071242
Adjacent sequences: A062176 A062177 A062178 this_sequence A062180 A062181 A062182
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KEYWORD
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base,easy,nonn
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AUTHOR
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Vladeta Jovovic (vladeta(AT)Eunet.yu), Jun 12 2001
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 08 2001
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