|
Search: id:A027930
|
|
| |
|
| 1, 3, 8, 21, 54, 133, 309, 674, 1383, 2683, 4950, 8735, 14820, 24285, 38587, 59652, 89981, 132771, 192052, 272841, 381314, 524997, 712977, 956134, 1267395, 1662011, 2157858, 2775763, 3539856, 4477949, 5621943, 7008264
(list; graph; listen)
|
|
|
OFFSET
|
4,2
|
|
|
FORMULA
|
a(n)=sum(binomial(n-k, 7-2k), k=0..3). - Len Smiley (smiley(AT)math.uaa.alaska.edu), Oct 20 2001
a(n)=C(n,n-1)+C(n+1,n-2)+C(n+2,n-3)+C(n+3,n-4), n>=1 . - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 29 2007
a(n)= 8*a(n-1) -28*a(n-2) +56*a(n-3) -70*a(n-4) +56*a(n-5) -28*a(n-6) +8*a(n-7) -a(n-8). G.f.: x^4*(x^2-x+1)*(x^4-4*x^3+7*x^2-4*x+1)/(x-1)^8. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 05 2009]
|
|
MAPLE
|
seq(binomial(n, n-1)+binomial(n+1, n-2)+binomial(n+2, n-3)+binomial(n+3, n-4), n=1..32); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 29 2007
|
|
CROSSREFS
|
Sequence in context: A014396 A039671 A166287 this_sequence A038200 A030015 A103446
Adjacent sequences: A027927 A027928 A027929 this_sequence A027931 A027932 A027933
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Clark Kimberling (ck6(AT)evansville.edu)
|
|
|
Search completed in 0.002 seconds
|
