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A260618 Irregular triangle read by rows: denominators of the expansion of k/n using the greedy algorithm, 1<=k<=n. 1
1, 2, 1, 3, 2, 6, 1, 4, 2, 2, 4, 1, 5, 3, 15, 2, 10, 2, 4, 20, 1, 6, 3, 2, 2, 6, 2, 3, 1, 7, 4, 28, 3, 11, 231, 2, 14, 2, 5, 70, 2, 3, 42, 1, 8, 4, 3, 24, 2, 2, 8, 2, 4, 2, 3, 24, 1, 9, 5, 45, 3, 3, 9, 2, 18, 2, 6, 2, 4, 36, 2, 3, 18, 1, 10, 5, 4, 20, 3, 15, 2, 2, 10, 2, 5, 2, 4, 20, 2, 3, 15, 1, 11, 6, 66, 4, 44, 3, 33, 3, 9, 99, 2, 22, 2, 8, 88, 2, 5, 37, 4070, 2, 4, 15, 660, 2, 3, 14, 231, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..1031

EXAMPLE

Triangle begins ({} included for fraction separation}):

{1};

{2}, {1};

{3}, {2, 6}, {1};

{4}, {2}, {2, 4}, {1};

{5}, {3, 15}, {2, 10}, {2, 4, 20}, {1};

{6}, {3}, {2}, {2, 6}, {2, 3}, {1};

{7}, {4, 28}, {3, 11, 231}, {2, 14}, {2, 5, 70}, {2, 3, 42}, {1};

{8}, {4}, {3, 24}, {2}, {2, 8}, {2, 4}, {2, 3, 24}, {1};

{9}, {5, 45}, {3}, {3, 9}, {2, 18}, {2, 6}, {2, 4, 36}, {2, 3, 18}, {1};

{10}, {5}, {4, 20}, {3, 15}, {2}, {2, 10}, {2, 5}, {2, 4, 20}, {2, 3, 15}, {1};

{11}, {6, 66}, {4, 44}, {3, 33}, {3, 9, 99}, {2, 22}, {2, 8, 88}, {2, 5, 37, 4070}, {2, 4, 15, 660}, {2, 3, 14, 231}, {1};

PROG

(PARI)

rep(f)={L=List(); while(f<>0, my(t=ceil(1/f)); listput(L, t); f-=1/t); Vec(L)}

row(n)={concat(apply(k->rep(k/n), [1..n]))}

for(n=1, 11, print(row(n))) \\ Andrew Howroyd, Feb 26 2018

CROSSREFS

Cf. A050205, A050206, A050210, A098853, A100140.

Sequence in context: A266138 A014000 A075257 * A306286 A226651 A073711

Adjacent sequences:  A260615 A260616 A260617 * A260619 A260620 A260621

KEYWORD

nonn,tabf

AUTHOR

Matthew Campbell, Sep 17 2015

STATUS

approved

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Last modified May 19 12:48 EDT 2019. Contains 323393 sequences. (Running on oeis4.)