login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A050205
Triangle read by rows: number of terms in unit fraction representation of k/n using the greedy algorithm, 1<=k<=n-1.
5
1, 1, 2, 1, 1, 2, 1, 2, 2, 3, 1, 1, 1, 2, 2, 1, 2, 3, 2, 3, 3, 1, 1, 2, 1, 2, 2, 3, 1, 2, 1, 2, 2, 2, 3, 3, 1, 1, 2, 2, 1, 2, 2, 3, 3, 1, 2, 2, 2, 3, 2, 3, 4, 4, 4, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 3, 1, 2, 3, 3, 3, 3, 2, 3, 3, 3, 3, 4, 1, 1, 2, 2, 2, 3, 1, 2, 2, 3, 3, 3, 4, 1, 2, 1, 2, 1, 2, 3, 2, 2, 2, 3
OFFSET
2,3
LINKS
Eric Weisstein's World of Mathematics, Unit Fraction.
EXAMPLE
2/3 = 1/2 + 1/6. So T(3,2) = 2.
n\k | 1 2 3 4 5 6 7 8
----*------------------------
2 | 1;
3 | 1, 2;
4 | 1, 1, 2;
5 | 1, 2, 2, 3;
6 | 1, 1, 1, 2, 2;
7 | 1, 2, 3, 2, 3, 3;
8 | 1, 1, 2, 1, 2, 2, 3;
9 | 1, 2, 1, 2, 2, 2, 3, 3;
CROSSREFS
Cf. A050206, A050210 (Largest denominator), A260618.
Sequence in context: A025836 A029319 A243987 * A281530 A340260 A175190
KEYWORD
nonn,easy,tabl
EXTENSIONS
Offset changed to 2 by Seiichi Manyama, Sep 18 2022
STATUS
approved