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!)
A024162 Number of incongruent integer-sided triangles with sides a,b,c, a<b<c, a+b+c=n. 0
0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 2, 1, 3, 2, 4, 2, 5, 4, 7, 4, 8, 6, 10, 6, 11, 9, 14, 9, 16, 12, 18, 12, 21, 15, 24, 16, 25, 20, 30, 19, 33, 25, 33, 25, 40, 28, 44, 30, 44, 36, 52, 34, 55, 42, 56, 42, 65, 44, 70, 49, 67, 56, 78, 52, 85, 64, 83, 63, 96, 66, 102, 72, 95, 81, 113, 75, 120, 88, 115, 90 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,13

REFERENCES

A. M. Yaglom and I. M. Yaglom: Challenging Mathematical Problems with Elementary Solutions. Vol. I. Combinatorial Analysis and Probability Theory. New York: Dover Publications, Inc., 1987, p. 8, #30 (First published: San Francisco: Holden-Day, Inc., 1964)

LINKS

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

FORMULA

For n=0..11 (mod 12), a(n) is respectively (n^2 + 6n - 7)/48, (n^2 - 4)/48, (n^2 + 6n + 21)/48, (n^2 - 16)/48, (n^2 + 6n - 7)/48, (n^2 + 12)/48, (n^2 + 6n + 5)/48, (n^2 - 16)/48, (n^2 + 6n + 9)/48, (n^2 - 4)/48, (n^2 + 6n + 5)/48

CROSSREFS

Sequence in context: A308307 A147541 A308308 * A334677 A179080 A294199

Adjacent sequences:  A024159 A024160 A024161 * A024163 A024164 A024165

KEYWORD

dead

EXTENSIONS

Apparently an erroneous version of A005044. For example a(18) should be 3 not 2.

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 September 27 16:20 EDT 2020. Contains 337383 sequences. (Running on oeis4.)