25363747

Appears in sequences

• 2*a(n)^2 + 7 is a square.at n=19A077442
• a(0) = -1, a(1) = 2; a(n) = 2*a(n-1) + a(n-2).at n=20A078343
• Start with the sequence S(0)={1,1} and for k>0 define S(k) to be I(S(k-1)) where I denotes the operation of inserting, for i=1,2,3..., the term a(i)+a(i+1) between any two terms for which 4a(i+1)<=5a(i). The listed terms are the initial terms of the limit of this process as k goes to infinity.at n=38A082981
• Part of the y solutions of the Pell equation x^2 - 2*y^2 = +7.at n=9A253811
• a(n) = 2*a(n - 2) + a(n - 4) with a(0) = a(1) = 2, a(2) = 1, a(3) = 3.at n=39A266504