[seqfan] Primitive version of A091784
David Corneth
davidacorneth at gmail.com
Mon Aug 22 22:05:40 CEST 2016
Hi all,
A091784 is "Numbers n with digits in increasing order such that sum of the
reciprocal of digits is an integer."
I think we can define a primitive version for this one:
"Numbers n with digits in increasing order such that the sum of the
reciprocal of digits is an integer but no subset of digits has that
property."
This sequence is finite. Let E be a term. E is 1, 22, 333, ..., 999999999
OR has the following property:
Let E_d be the frequence of digit d in E. Then E_d < d.
This means there are 8! other candidates E. With this sequence, all terms
of A091784 can be constructed.
Best,
David
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