26269

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 64.at n=0A031652
• Expansion of (5 + 6*x + 3*x^2 - 2*x^3) / (1 - 2*x - 2*x^2 - 2*x^3 + x^4) in powers of x.at n=8A071101
• Given the infinite continued fraction (1+i)+((1+i)/(1+i)+((1+i)/((1+i)+...)))), where i is the square root of (-1), this is the denominator of the convergents.at n=10A093727
• Number of valleys (i.e., (1,-1) followed by (1,1)) at level zero in all peakless Motzkin paths of length n+6 (can be easily translated into RNA secondary structure terminology).at n=10A110335
• Small-number statistic from the enumeration of domino tilings of a 3-pillow of order n.at n=19A112835
• a(n) = 2*a(n-1) + 2*a(n-2) + 2*a(n-3) - a(n-4); a(0)=0, a(1)=1, a(2)=2, a(3)=5.at n=11A138573
• A024581 / [1,2,3,...].at n=11A153582
• Expansion of x * (1 + x) * (1 - x^2) * (1 + x^3) / (1 - 2*x^2 - 2*x^4 - 2*x^6 + x^8) in powers of x.at n=22A206625
• Number of length 5+4 0..n arrays with every five consecutive terms having four times some element equal to the sum of the remaining four.at n=7A249661
• a(n) = 24*n^2 + 52*n + 29.at n=32A258721
• Consider a number x. Take the sum of its digits. Repeat the process deleting the first addendum and adding the previous sum. The sequence lists the numbers that after some iterations reach the arithmetic derivative of x.at n=26A269312