70737

Appears in sequences

• Base-4 digits are, in order, the first n terms of the periodic sequence with initial period 1,0,1.at n=8A033122
• Base 8 digits are, in order, the first n terms of the periodic sequence with initial period 2,1.at n=5A037493
• a(n) = Sum_{1<=k<=n, gcd(k,n)=1} 2^(k-1).at n=17A054432
• a(n) = 196*n^2 - n.at n=18A158003
• a(n) = 361*n^2 - 19.at n=13A158595
• a(n) = n*(n + 1)*(n + 2)*(9*n - 7)/12.at n=17A264852
• Number of 2Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2, 3 or 4 neighboring 1s.at n=10A297763
• G.f. A(x,y) satisfies: y = f(x,A(x,y)), where f(x,y) = Sum_{n=-oo..oo} x^(n*(n+1)/2) * y^(n*(n-1)/2) is Ramanujan's theta function.at n=45A354649
• G.f. A(x,y) satisfies: -y = f(-x,-A(x,y)), where f(x,y) = Sum_{n=-oo..oo} x^(n*(n+1)/2) * y^(n*(n-1)/2) is Ramanujan's theta function.at n=45A354650
• Column 3 of triangle A354650: a(n) = A354650(n,3), for n >= 1.at n=5A354656
• G.f. A(x,y) satisfies: x*y*A(x,y) = Sum_{n=-oo..+oo} (-1)^n * x^(n*(n+1)/2) * A(x,y)^n, with coefficients T(n,k) of x^n*y^k in A(x,y) given as a triangle read by rows.at n=48A355360
• a(n) = Sum_{k=0..floor((2*n+1)/7)} binomial(2*k+1,2*n-7*k+1).at n=37A392488