20262

Appears in sequences

• Numbers k such that 17*2^k - 1 is prime.at n=27A001774
• a(n) = (d(n)-r(n))/2, where d = A026037 and r is the periodic sequence with fundamental period (1,0,0,1).at n=47A026038
• Numbers k such that 295*2^k + 1 is prime.at n=26A053364
• Total number of nodes in all rooted trees with n nodes.at n=10A055544
• Least m such that reverse(sigma(m)) = sigma(m+n).at n=42A071813
• Triangle of counts of s-clusters in n X n (0,1)-matrices for s=0, 1, ....at n=14A086266
• Number of subsets of {1, ..., n} that are sum-free but not double-free.at n=22A088811
• Average of 4 primes where the integer Schwarzian derivative is zero.at n=21A094903
• Take an n X n square grid of points in the plane; a(n) = number of non-isomorphic ways to divide the points into two sets using a straight line.at n=26A116696
• Number of ordered triples (w,x,y) with all terms in {1,...,n} and 2w^3>=x^3+y^3.at n=35A211804
• Sum of all odd numbers in Collatz (3x+1) trajectory of n.at n=26A213916
• Sum of all odd numbers in Collatz (3x+1) trajectory of n.at n=53A213916
• Numbers k such that Bernoulli number B_{k} has denominator 64722.at n=14A295592
• Number of binary strings of length n with more 000 than 001 substrings.at n=16A371662