The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A104583 Triangle read by rows: T(i,j) is the (i,j)-entry (1 <= j <= i) of the product A*B of the matrices A = [1; 3,1; 5,3,1; 7,5,3,1; ...]; B = [1; 1,2; 1,2,1; 1,2,1,2; ...] (both infinite lower triangular matrices). 0
 1, 4, 2, 9, 8, 1, 16, 18, 4, 2, 25, 32, 9, 8, 1, 36, 50, 16, 18, 4, 2, 49, 72, 25, 32, 9, 8, 1, 64, 98, 36, 50, 16, 18, 4, 2, 81, 128, 49, 72, 25, 32, 9, 8, 1, 100, 162, 64, 98, 36, 50, 16, 18, 4, 2, 121, 200, 81, 128, 49, 72, 25, 32, 9, 8, 1, 144, 242, 100, 162, 64, 98, 36, 50, 16, 18 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Table of n, a(n) for n=0..75. FORMULA T(i, j) = (i-j+1)^2 if j <= i and j is odd; 2(i-j+1)^2 if j <= i and j is even; 0 if j > i. - Emeric Deutsch, Mar 23 2005 EXAMPLE The first few rows are: 1; 4, 2; 9, 8, 1; 16, 18, 4, 2; 25, 32, 9, 8, 1; 36, 50, 16, 18, 4, 2; 49, 72, 25, 32, 9, 8, 1; ... MAPLE T:=proc(i, j) if j<=i and j mod 2=1 then (i-j+1)^2 elif j<=i and j mod 2 =0 then 2*(i-j+1)^2 else 0 fi end: for i from 1 to 13 do seq(T(i, j), j=1..i) od; # yields sequence in triangular form # Emeric Deutsch, Mar 23 2005 CROSSREFS Cf. A002411. Row sums yield the pentagonal pyramidal numbers (A002411). Sequence in context: A200639 A365255 A243968 * A278103 A249327 A182728 Adjacent sequences: A104580 A104581 A104582 * A104584 A104585 A104586 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Mar 16 2005 EXTENSIONS More terms from Emeric Deutsch, Mar 23 2005 STATUS approved

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.

Last modified August 11 04:26 EDT 2024. Contains 375059 sequences. (Running on oeis4.)