login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A084840 Write the numbers 1, 2, ... in a triangle with n terms in the n-th row; a(n) = number of abundant integers in n-th row. 1
0, 0, 0, 0, 1, 2, 1, 2, 2, 2, 3, 3, 4, 4, 4, 2, 4, 4, 4, 7, 5, 4, 6, 5, 7, 6, 8, 7, 6, 9, 7, 8, 9, 8, 9, 9, 8, 10, 10, 10, 10, 10, 12, 11, 9, 12, 11, 11, 14, 10, 14, 14, 13, 14, 13, 13, 14, 16, 15, 13, 16, 15, 17, 17, 15, 18, 14, 17, 16, 19, 18, 19, 15, 20, 19, 18, 20, 20, 18, 20, 21, 22 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Table of n, a(n) for n=1..82.

EXAMPLE

Triangle begins

1 (0 abundant)

2 3 (0 abundant)

4 5 6 (0 abundant)

7 8 9 10 (0 abundant)

11 12 13 14 15 (1 abundant)

16 17 18 19 20 21 (2 abundant)

22 23 24 25 26 27 28 (1 abundant)

CROSSREFS

Cf. A005101.

Sequence in context: A319821 A024154 A117875 * A029278 A125950 A323088

Adjacent sequences:  A084837 A084838 A084839 * A084841 A084842 A084843

KEYWORD

easy,nonn

AUTHOR

Jason Earls, Jun 08 2003

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 25 07:29 EDT 2020. Contains 334584 sequences. (Running on oeis4.)