1039681

Properties

Appears in sequences

• Numerators of continued fraction convergents to sqrt(10).at n=8A005667
• Numbers whose square with its last digit deleted is also a square.at n=29A031149
• Numerators of continued fraction convergents to sqrt(40).at n=7A041066
• Numerators of continued fraction convergents to sqrt(90).at n=7A041160
• Numerators of continued fraction convergents to sqrt(160).at n=15A041294
• Numerators of continued fraction convergents to sqrt(360).at n=7A041682
• Numerators of continued fraction convergents to sqrt(490).at n=9A041934
• Numerators of continued fraction convergents to sqrt(640).at n=11A042228
• Least number starting a chain of exactly 2n-1 consecutive integers that do not have totient inverses.at n=19A063512
• Chebyshev T(n,19) polynomial.at n=4A078986
• Duplicate of A005667.at n=8A084133
• Initial terms of chains consisting of four consecutive integers, for none of which is the value of sigma-function divisible by six.at n=28A097020
• Expansion of g.f. x*(1+x+2*x^2+2*x^3+5*x^4+5*x^5-3*x^6+2*x^7-x^8-x^9)/(1-6*x^6-x^12).at n=49A116559
• Primes of the form 5k^2 + 1.at n=26A137530
• a(n) = ChebyshevT(4, n).at n=19A144130
• Primes of the form T_4(n), where T_4(x) = 8x^4 - 8x^2 + 1 is the fourth Chebyshev polynomial (of the first kind).at n=7A144131
• Primes of the form 648*k^2 + 72*k + 1.at n=14A154510
• a(n) = 10368*n^2 + 288*n + 1.at n=9A157326
• Array of ((k^n)+(k^(-n)))/2 where k=(sqrt(x^2+1)+x)^2 for integers x>=1.at n=23A188645
• Number of nonnegative integer arrays of length n+5 with new values 0 upwards introduced in order, no three adjacent elements equal, and containing the value n+1.at n=15A211838