19901

Appears in sequences

• Denominators of continued fraction convergents to fifth root of 5.at n=11A002363
• T(n,0) + T(n,1) + ... + T(n,n), T given by A026568.at n=11A026580
• a(n) = (L(n) + L(2*n))/2, where L = A000032 (the Lucas sequence).at n=11A049680
• Trajectory of n under the Reverse and Add! operation carried out in base 3 (presumably) does not reach a palindrome and (presumably) does not join the trajectory of any term m < n.at n=42A077405
• Third row of Pascal-(1,4,1) array A081579.at n=40A081587
• Counterexamples to the conjecture that an even, prime-indexed triangular plus 1 equals a prime or that an odd, prime-indexed triangular minus 2 equals a prime.at n=16A097785
• Triangle of coefficients of certain polynomials used with prime numbers as variables in the computation of the array A103728.at n=30A103718
• Column m=2 sequence of triangle A103718(n,m), n >= 0 (without leading zeros).at n=5A103719
• Numbers k such that (2*k)!/(2*(k!)^2)+1 is prime.at n=46A112863
• Numbers k such that k = T(x) + T(y) where T(m) is the m-th triangular number and k is concatenate(x, y) in base 10.at n=3A113796
• Number of 1-sided polykites with n cells.at n=9A151528
• Number of (n+1)X(n+1) -4..4 symmetric matrices with every 2X2 subblock having sum zero and one, three or four distinct values.at n=5A211496
• First quadrisection of A332843.at n=19A330522