20388

Appears in sequences

• Number of balanced ordered trees with n nodes.at n=19A007059
• Duplicate of A007059.at n=19A038495
• Bisection of A007059.at n=9A066351
• Number of compositions of the integer n in which the first part is >= the other parts.at n=18A079500
• The number of rectangles (orthogonal or not) with corners on an n X n grid of points.at n=14A085582
• Numbers k > 1 for which floor(b(k)) = floor(b(k-1)), where b(m) = Sum_{j=1..m} (j/(j+2)).at n=17A133470
• Irregular triangle: nonzero differences A179313(n,k) - A127742(n,k), read by rows.at n=45A179315
• Expansion of 1 / (1 - Sum_{k>=1} k^(k-2) * x^k ).at n=7A277611
• G.f. satisfies: A(x - A(x) + A(x)^2) = -x^4.at n=10A291189
• The number of solutions to phi(x) = phi(x+1) below 10^n, where phi(x) is the Euler totient function.at n=13A300285
• Integers that concatenate 3 counts: the number of terms in the sequence so far, the number of primes in the sequence so far, the number of digits in the sequence so far, with a(1)= 113. The sequence is always extended with the smallest available integer not leading to a contradiction or a dead end.at n=19A309617
• Absolute multiplicative persistence: a(n) is the least number with multiplicative persistence n for some base b > 1.at n=16A330152
• Number of integer partitions of n with more than one non-mode.at n=37A363124
• G.f. satisfies A(x) = 1 + x*A(x) / (1 + x*A(x))^4.at n=10A365087
• Centered 29-gonal numbers.at n=37A389798