0,2

If a 2-set Y and an (n-3)-set Z are disjoint subsets of an n-set X then a(n-9) is the number of 9-subsets of X intersecting both Y and Z. - Milan R. Janjic (agnus(AT)blic.net), Sep 08 2007

8-dimensional square numbers, seventh partial sums of binomial transform of [1,2,0,0,0,...]. a(n)=sum{i=0,n,C(n+7,i+7)*b(i)}, where b(i)=[1,2,0,0,0,...]. [From Borislav St. Borisov (b.st.borisov(AT)abv.bg), Mar 05 2009]

A. H. Beiler, Recreations in the Theory of Numbers, Dover, N.Y., 1964, pp. 194-196.

Milan Janjic, Two Enumerative Functions

Index entries for sequences related to Chebyshev polynomials.

a(n)= ((-1)^n)*A053120(2*n+8, 8)/2^7 (1/128 of ninth unsigned column of Chebyshev T-triangle, zeros omitted).

G.f. (1+x)/(1-x)^9.

a(n)=2*C(n+8, 8)-C(n+7, 7). - Paul Barry (pbarry(AT)wit.ie), Mar 04 2003

Equals A027803/35 = C(n+4, n)*C(n+7, 4)/35 - Zerinvary Lajos (zlaja(AT)freemail.hu), May 25 2005

a(n)=C(n+7,7)+2*C(n+7,8) [From Borislav St. Borisov (b.st.borisov(AT)abv.bg), Mar 05 2009]

a:=n->(sum((numbcomp(n, 8)), j=5..n)):seq(a(n)/4, n=8..36); [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Aug 26 2008]

s1=s2=s3=s4=s5=s6=0; lst={}; Do[s1+=n^2; s2+=s1; s3+=s2; s4+=s3; s5+=s4; s6+=s5; AppendTo[lst, s6], {n, 0, 7!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Jan 15 2009]

Partial sums of A050486.

Cf. A005585, A040977, A050486 [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Jan 15 2009]

Sequence in context: A007035 A093187 A152762 this_sequence A036600 A058645 A057586

Adjacent sequences: A053344 A053345 A053346 this_sequence A053348 A053349 A053350

easy,nonn

Barry E. Williams, Jan 06 2000