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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A115294 Diagonal sums of correlation triangle for (1+x)^3/(1-x). 1
 1, 4, 11, 25, 47, 79, 122, 175, 239, 314, 399, 495, 602, 719, 847, 986, 1135, 1295, 1466, 1647, 1839, 2042, 2255, 2479, 2714, 2959, 3215, 3482, 3759, 4047, 4346, 4655, 4975, 5306, 5647, 5999, 6362, 6735, 7119, 7514, 7919, 8335, 8762, 9199, 9647, 10106 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Diagonal sums of number triangle A115292. LINKS Index entries for linear recurrences with constant coefficients, signature (2,-1,1,-2,1). FORMULA G.f.: (1+x)^2*(1+x^2)^3/((1-x)^2*(1-x^3)); a(n)=sum{k=0..floor(n/2), sum{j=0..n-k, [j<=k]*A115291(k-j)*[j<=n-2k]*A115291(n-2k-j)}}. MATHEMATICA LinearRecurrence[{2, -1, 1, -2, 1}, {1, 4, 11, 25, 47, 79, 122, 175, 239}, 50] (* Harvey P. Dale, Jun 11 2017 *) CROSSREFS Sequence in context: A192597 A181946 A176959 * A110610 A051462 A006004 Adjacent sequences:  A115291 A115292 A115293 * A115295 A115296 A115297 KEYWORD easy,nonn AUTHOR Paul Barry, Jan 19 2006 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 September 21 07:28 EDT 2021. Contains 347596 sequences. (Running on oeis4.)