A278108 - OEIS

A278108

Irregular triangle read by rows: T(n,k) = floor(n/k^2) for 1 <= k^2 <= n.

1, 2, 3, 4, 1, 5, 1, 6, 1, 7, 1, 8, 2, 9, 2, 1, 10, 2, 1, 11, 2, 1, 12, 3, 1, 13, 3, 1, 14, 3, 1, 15, 3, 1, 16, 4, 1, 1, 17, 4, 1, 1, 18, 4, 2, 1, 19, 4, 2, 1, 20, 5, 2, 1, 21, 5, 2, 1, 22, 5, 2, 1, 23, 5, 2, 1, 24, 6, 2, 1, 25, 6, 2, 1, 1, 26, 6, 2, 1, 1, 27, 6, 3, 1, 1, 28, 7, 3, 1, 1, 29, 7, 3, 1, 1

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

The row length sequence is A000196.

LINKS

Jason Kimberley, Table of n, a(n) for n = 1..20615 (the first 1000 rows of the triangle)

EXAMPLE

The first 27 rows are:

4, 1;

5, 1;

6, 1;

7, 1;

8, 2;

9, 2, 1;

10, 2, 1;

11, 2, 1;

12, 3, 1;

13, 3, 1;

14, 3, 1;

15, 3, 1;

16, 4, 1, 1;

17, 4, 1, 1;

18, 4, 2, 1;

19, 4, 2, 1;

20, 5, 2, 1;

21, 5, 2, 1;

22, 5, 2, 1;

23, 5, 2, 1;

24, 6, 2, 1;

25, 6, 2, 1, 1;

26, 6, 2, 1, 1;

27, 6, 3, 1, 1;

PROG

(Magma) [n div k^2:k in[1..Isqrt(n)], n in[1..27]];

CROSSREFS

Cf. A000196, A010766, A277646, A277647, A278109.

Sequence in context: A292032 A097150 A319826 * A302786 A322026 A363247

Adjacent sequences: A278105 A278106 A278107 * A278109 A278110 A278111

KEYWORD

nonn,easy,tabf

AUTHOR

Jason Kimberley, Feb 01 2017

STATUS

approved