22425

Appears in sequences

• a(n) = floor(n*(n-1)*(n-2)*(n-3)/16).at n=26A011926
• Larger members of primitive phi-amicable pairs.at n=15A121249
• Number of proper divisors of n-th even perfect number.at n=22A133033
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (0, -1, 0), (0, 1, -1), (1, 1, 0)}.at n=9A149173
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (0, 1, 0), (0, 1, 1), (1, 0, 1), (1, 1, -1)}.at n=7A151161
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 491", based on the 5-celled von Neumann neighborhood.at n=30A272541
• Let p = n-th prime == 7 mod 8; a(n) = sum of quadratic residues mod p that are < p/2.at n=26A282039
• a(n) is the smallest m such that p = n-th popular prime = A385503(n) is uniquely popular on the interval [2,m] or -1 if p is never uniquely popular.at n=6A289662
• Numbers k such that k=(a+b)*c=a*b+c for more than one triple (a,b,c) with 1<c<a<=b.at n=2A329169
• Number of compositions (ordered partitions) of n into distinct nonprime parts.at n=50A331917
• a(n) = ((n + 1) - 9*(n + 1)^2 + 8*(n + 1)^3)/6.at n=25A331987
• Numbers k such that 6*17^k + 1 is prime.at n=16A332763
• Expansion of (-1 + Product_{k>=1} 1 / (1 + (-x)^k))^5.at n=22A341244