18805

Appears in sequences

• Let A(n) = #{(i,j,k): i^2 + j^2 + k^2 <= n}, V(n) = (4/3)*Pi*n^(3/2), P(n) = A(n) - V(n); A000092 gives values of n where |P(n)| sets a new record; sequence gives A(A000092(n)).at n=17A000413
• Number of series-reduced planted trees with n leaves of 2 colors.at n=7A050381
• Number of compositions of n with exactly 4 adjacent equal parts.at n=13A106360
• Partial sum of Perrin numbers.at n=30A193744
• Positions of pandigital 10-digit numbers after the decimal point in the decimal expansion of Pi.at n=8A280183
• Start from the singleton set S = {n}, and unless 1 is already a member of S, generate on each iteration a new set where each odd number k is replaced by 3k+1, and each even number k is replaced by 3k+1 and k/2. a(n) is the total size of the set from the singleton through after the first iteration which has produced 1 as a member, inclusive.at n=26A291213
• Number of n X 3 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 0, 1 or 2 neighboring 1s.at n=4A297369
• T(n,k)=Number of nXk 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 0, 1 or 2 neighboring 1s.at n=25A297374
• Number of 5Xn 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 0, 1 or 2 neighboring 1s.at n=2A297378
• Array read by antidiagonals: T(n,k) is the number of series-reduced rooted trees with n leaves of k colors.at n=43A319254
• Numerator of the average distance among first n primes.at n=40A332094
• Number of non-strict integer partitions of n with at least one part of odd multiplicity that is not the first or last.at n=37A349796