11309769

Appears in sequences

• a(n) = floor( a(n-1)/(sqrt(2) - 1) ), with a(0) = 1.at n=19A024537
• a(n) and floor(a(n)/2) are both squares; i.e., squares which remain squares when written in base 2 and last digit is removed.at n=6A055792
• a(n) and floor(a(n)/8) are both squares; i.e., squares that remain squares when written in base 8 and last digit is removed.at n=11A055872
• Numbers k such that k*(k - 1)/2 is a square.at n=10A055997
• a(n) = (4*n^2 - 1)^2.at n=29A069075
• Safe perfect powers: perfect powers n such that (n-1)/2 is also a perfect power.at n=5A075127
• Numbers n such that n-1 and n are a pair of consecutive powerful numbers.at n=9A078326
• Repeatedly multiply (1,0,0) by ([1,2,2],[2,1,2],[2,2,3]); sequence gives leading entry.at n=10A090390
• Expansion of g.f. (1-x-x^2)/(1-x-3*x^2-x^3).at n=20A097075
• a(n) = 2*a(n-1) + 2*a(n-3) + a(n-4), a(0) = 1, a(1) = 4, a(2) = 9, a(3) = 20.at n=18A111587
• Consider all Pythagorean triples (X,X+1,Z) ordered by increasing Z; sequence gives Z-X values.at n=9A115599
• Duplicate of A078326.at n=9A118893
• Binomial transform of 1,0,1,0,2,0,4,0,8,0,16,...at n=20A171842
• Sin(arcsin(n) - 4 arccos(n))^2.at n=3A239610