24721

Appears in sequences

• Numbers n such that sigma(phi(n))/sigma(n) = 2.at n=36A067382
• Ratios of successive terms of A080985.at n=3A080987
• Composite numbers such that all divisors >1 have the same number of 1's in binary representation.at n=39A089042
• Graham-Pollak sequence with initial term 8.at n=23A091523
• Sum of largest parts (counted with multiplicity) of all partitions of n into odd parts.at n=41A092310
• a(n) = n! * Sum_{k=0..n} Stirling2(n,k)/k!.at n=6A119392
• 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, 0, 0), (0, -1, 1), (1, -1, 1), (1, 0, -1), (1, 1, 1)}.at n=8A149768
• Least j such that 6*p(j)*M(n)-1 is prime with p(j)=j-th prime and M(n) = Mersenne prime.at n=29A157333
• The least number s having exactly n fours in the continued fraction of sqrt(s).at n=19A206584
• Number of partitions of n with up to two distinct kinds of 1.at n=41A320689
• Odd composite integers m such that U(m)^2 == 1 (mod m) and V(m) == 6 (mod m), where U(m) and V(m) are the m-th generalized Lucas and Pell-Lucas numbers of parameters a=6 and b=-1, respectively.at n=22A337629
• Odd composite integers m such that A085447(m) == 6 (mod m).at n=29A338078
• a(0) = 1; thereafter a(n) = floor((9/4)*a(n-1)) + 1.at n=12A361507