2419200

Appears in sequences

• Numbers m such that uphi(sigma(m)) = 2m, where the unitary phi function (A047994) is defined by: if x = p1^r1*p2^r2*p3^r3*... then uphi(x) = (p1^r1 - 1)*(p2^r2 - 1)*(p3^r3 - 1)*...at n=18A030165
• There exists some k>0 such that n is the product of (k + digits of n).at n=28A055482
• Sum of divisors of central binomial coefficient binomial(n, floor(n/2)).at n=21A064139
• Duplicate of A067819.at n=10A066972
• Sum of the divisors of binomial(2n,n).at n=10A067819
• Numbers n such that n=(d_1+6)*(d_2+6)*...*(d_k+6) where d_1 d_2 ... d_k is the decimal expansion of n.at n=6A097372
• Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1),U=(1,2), or d=(1,-1) and have k peaks (i.e., ud and Ud's).at n=39A108425
• a(1)=1. a(n+1) = n!/lcm(a(1),a(2),...,a(n)).at n=20A131120
• a(n) = A131120(n+1)/n.at n=20A131121
• Triangular sequence from coefficients of the umbral calculus expansion of a Golden -Mean Bernoulli function(A001898): p(x,t)=t*phi^(x*t)/(phi^t - 1), where the golden ratio replaces "e".at n=38A137524
• Numbers n such that sigma(x) = n has more solutions x than any smaller n.at n=34A145899
• Product of nonzero remainders of n mod k, for k = 1,2,3,...,n.at n=16A173392
• a(n) = A002952(n) + A002953(n).at n=23A180277
• Product of remainders of n mod k, for k = 2,3,4,...,n-1.at n=16A180491
• Product of remainders of prime(n) mod k, for k = 2,3,4,...,prime(n)-1.at n=6A180492
• The n-th derivative of x^10 evaluated at x=2.at n=6A189071
• Denominator of the rational part of the sum of reciprocals of even powers of even numbers, i.e., Sum_{k>=1} 1/(2*k)^(2*n).at n=3A276595
• Number of ways to occupy n unlabeled phone booths in a circle one by one, each time picking a phone booth adjacent to the smallest number of previously occupied phone booths.at n=12A276657
• Triangular array read by rows. T(n,k) is the number of rooted labeled trees on n nodes with exactly k vertices whose unique descendent is a leaf, n >= 1, 0 <= k <= floor((n-1)/2) + delta_{2,n}.at n=30A284417
• Indices of records in A063974.at n=37A289132