A052146 - OEIS

A052146

a(n) = floor((sqrt(1+8*n)-3)/2).

0, 0, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11

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

OFFSET

1,6

REFERENCES

R. P. Stanley, Enumerative Combinatorics, Cambridge, Vol. 2, 1999; see Problem 7.2(d).

LINKS

Table of n, a(n) for n=1..84.

MATHEMATICA

Floor[(Sqrt[1 + 8 Range[100]] - 3)/2] (* Wesley Ivan Hurt, Oct 02 2021 *)

CROSSREFS

Sequence in context: A104147 A227568 A232746 * A097882 A108955 A108956

Adjacent sequences: A052143 A052144 A052145 * A052147 A052148 A052149

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jan 23 2000

STATUS

approved