18185

Appears in sequences

• Define the sequence T(a(0), a(1)) by a(n+2) is the greatest integer such that a(n+2)/a(n+1) < a(n+1)/a(n) for n >= 0. This is T(7,50).at n=4A022037
• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = floor(n/2), s = (natural numbers >= 3), t = (Fibonacci numbers).at n=15A024315
• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers >= 3), t = (F(2), F(3), F(4), ...).at n=14A024878
• a(0)=1; a(1)=1; a(n)= a(n-1) + floor(sqrt(a(n-1)*a(n-2))) + floor(sqrt(a(n-3)*a(n-4))) + ....at n=16A043328
• Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 15.at n=21A051980
• Sum of n-th prime squared and n-th perfect square.at n=31A106587
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, -1), (0, 1, 1), (1, -1, -1), (1, 0, 1)}.at n=8A150150
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, -1), (0, 1, 1), (1, -1, -1), (1, 1, 0)}.at n=8A150151
• Positive numbers y such that y^2 is of the form x^2+(x+577)^2 with integer x.at n=8A159626
• Number of binary strings of length n with no substrings equal to 0010 0100 or 1001.at n=13A164491
• 3*n analog to Keith numbers.at n=13A282758
• a(n) = sum of the first n primes whose distance to next prime is 4.at n=40A360226