This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A058333 Number of 3 X 3 matrices with elements from [0,...,(n-1)] satisfying the condition that the middle element of each row or column is the difference of the two end elements (in absolute value). 0
 1, 16, 73, 208, 465, 896, 1561, 2528, 3873, 5680, 8041, 11056, 14833, 19488, 25145, 31936, 40001, 49488, 60553, 73360, 88081, 104896, 123993, 145568, 169825, 196976, 227241, 260848, 298033, 339040 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS If the "middle element" condition in the definition is also placed on the two diagonal lines of three in addition to each row and column, the sequence generated is the sequence of squares {1,4,9,16,...}. LINKS FORMULA The terms a(1) through a(30) are given by a(n)=(n^4+8n^3-10n^2+4n)/3. Empirical g.f.: x*(x+1)*(7*x^2-10*x-1) / (x-1)^5. - Colin Barker, Mar 29 2013 CROSSREFS Sequence in context: A299803 A299679 A300311 * A232337 A124894 A126403 Adjacent sequences:  A058330 A058331 A058332 * A058334 A058335 A058336 KEYWORD nonn AUTHOR John W. Layman, Dec 13 2000 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.

Last modified December 10 15:09 EST 2019. Contains 329896 sequences. (Running on oeis4.)