login
The OEIS is supported by the many generous donors to the OEIS 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

%I #5 Feb 19 2004 03:00:00

%S 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,

%T 18,12,21,15,24,16,25,20,30,19,33,25,33,25,40,28,44,30,44,36,52,34,55,

%U 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

%N Number of incongruent integer-sided triangles with sides a,b,c, a<b<c, a+b+c=n.

%D 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)

%F 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

%K dead

%O 1,13

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

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)