159140519

Appears in sequences

• a(n) = 6*a(n-1) - a(n-2) + 2 with a(0) = 0, a(1) = 3.at n=11A001652
• Related to Pythagorean triples: alternate terms of A001652 and A046090.at n=11A046727
• Expansion of 1/((1 - x)*(1 - 2*x - x^2)).at n=21A048739
• Pell oblongs.at n=11A084159
• Expansion of g.f. (1-x-x^2)/(1-x-3*x^2-x^3).at n=23A097075
• Pythagorean triples of nearly isosceles triangle.at n=30A114336
• Numbers k where d/k reaches a new record, with d the distance from the k-th triangular number to the nearest square.at n=30A229117
• Pairs of integers (a,b) such a^2 + (a+1)^2 = b^2.at n=22A261116