

A272082


Irregular triangle read by rows: strictly decreasing positive integer sequences in lexicographic order with the property that the sum of inverses is an integer.


4



1, 6, 3, 2, 6, 3, 2, 1, 12, 6, 4, 2, 12, 6, 4, 2, 1, 15, 10, 3, 2, 15, 10, 3, 2, 1, 15, 12, 10, 4, 2, 15, 12, 10, 4, 2, 1, 15, 12, 10, 6, 4, 3, 15, 12, 10, 6, 4, 3, 1, 18, 9, 3, 2, 18, 9, 3, 2, 1, 18, 12, 9, 4, 2, 18, 12, 9, 4, 2, 1, 18, 12, 9, 6, 4, 3, 18, 12
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OFFSET

1,2


LINKS



EXAMPLE

First 8 rows:
[1] because 1/1 is an integer
[6, 3, 2] because 1/6 + 1/3 + 1/2 = 1.
[6, 3, 2, 1] because 1/6 + 1/3 + 1/2 + 1/1 = 2.
[12, 6, 4, 2] because 1/12 + 1/6 + 1/4 + 1/2 = 1.
[12, 6, 4, 2, 1] because 1/12 + 1/6 + 1/4 + 1/2 + 1/1 = 2.
[15, 10, 3, 2] because 1/15 + 1/10 + 1/3 + 1/2 = 1.
[15, 10, 3, 2, 1] because 1/15 + 1/10 + 1/3 + 1/2 + 1/1 = 2.
[15, 12, 10, 4, 2] because 1/15 + 1/12 + 1/10 + 1/4 + 1/2 = 1.


CROSSREFS



KEYWORD

nonn,tabf


AUTHOR



STATUS

approved



