26352

Appears in sequences

• a(n)=Sum{T(n,k)*T(n,k+2)}, 0<=k<=2n-2, T given by A027926.at n=6A027996
• a(n) = n*(n^4 + 10*n^3 + 35*n^2 + 50*n + 144)/120.at n=17A051745
• a(n) = AlexanderPolynomial[n] defined as Det[Transpose[S]-n S] where S is Kronecker Product of two 2 X 2 Seifert matrices {{-1, 1}, {0, -1}} [X] {{-1, 1}, {0, -1}} = {{1, -1, -1, 1}, {0, 1, 0, -1}, {0, 0, 1, -1}, {0, 0, 0, 1}}.at n=13A138849
• Numbers n such that phi(n)=d_1!!*d_2!!*...*d_k!! where d_1 d_2 ... d_k is the decimal expansion of n.at n=19A139408
• a(1)=0, a(n) = n^3 - a(n-1).at n=36A153026
• Numbers n such that d(n + d(n)) = d(n), where d(n) is the sum of the distinct primes dividing n.at n=28A175760
• Numbers of the form p^4*q^3*r where p, q, and r are distinct primes.at n=32A179698
• The number of 2 X 2 symmetric positive definite matrices whose entries are integers x,y,z satisfying x^2 + y^2 + z^2 <= n^2.at n=37A219744
• a(1)=1, a(2)=2; thereafter a(n) = a(n-1) + a(n-1-(number of even terms so far)) + a(n-1-(number of odd terms so far)).at n=46A249039
• Number of n X 2 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.at n=25A252814
• G.f.: A(x) = Sum_{n>=0} x^n * (1+x)^(2*n^2) / A(x)^n.at n=8A321608
• G.f. = Phi^5, where Phi = g.f. for A028930.at n=20A328530
• a(n) = coefficient of 2^(1/3) in the expansion of (2^(1/3) + 2^(2/3))^n.at n=11A377118