70217

Appears in sequences

• sec(tanh(x)*exp(x))=1+1/2!*x^2+6/3!*x^3+21/4!*x^4+100/5!*x^5...at n=8A012662
• Denominators of continued fraction convergents to sqrt(217).at n=13A041405
• a(1) = 2; for n>=2, a(n) = 8*a(n-1) + 1.at n=5A132433
• The integer partitions of n taken as digits in base n+1 and listed in the Hindenburg order.at n=43A157406
• The y member of the positive proper fundamental solution (x = x2(n), y = y2(n)) of the second class for the Pell equation x^2 - D(n)*y^2 = +8 for odd D(n) = A263012(n).at n=9A264353