2162160

Appears in sequences

• a(n) = (2*n)!/(n+1)!.at n=7A001761
• Highly composite numbers: numbers n where d(n), the number of divisors of n (A000005), increases to a record.at n=40A002182
• Superabundant [or super-abundant] numbers: n such that sigma(n)/n > sigma(m)/m for all m < n, sigma(n) being A000203(n), the sum of the divisors of n.at n=32A004394
• Where records occur in A038548.at n=37A004778
• Numbers k such that sigma(k)/phi(k) sets a new record.at n=30A018894
• a(1)=1; for n > 1, a(n) is the smallest number with the same number of divisors as 2*a(n-1).at n=24A019505
• a(n) = 14*(n+1)*binomial(n+5,8).at n=8A027813
• a(n) = 99*(n+1)*binomial(n+5,12).at n=4A027817
• Triangular table of 2^n *(n+k)! / ((n-k)! * k! * 4^k).at n=41A043302
• Triangle of coefficients of certain Sheffer-polynomials.at n=28A048870
• a(n) = (n+8)!/8!.at n=6A049389
• Generalized Stirling number triangle of first kind.at n=21A051380
• Product of 6 consecutive integers.at n=14A053625
• Triangular array for David G. Cantor's sigma function.at n=44A055068
• Triangular array for David G. Cantor's sigma function.at n=42A055068
• Sixth (unsigned) column of triangle A062140 (generalized a=4 Laguerre).at n=4A062263
• Consider 2n tennis players; a(n) is the number of matches needed to let every possible pair play each other.at n=31A062346
• Numbers k that are repdigits in more bases (smaller than k) than any smaller number.at n=39A066044
• a(n) = (2^(n-1)/(2n)!)*Product_{k=1..n} q(k) where q(n) is the denominator of B(2n), the 2n-th Bernoulli number.at n=30A069267
• Least number m such that integer part of sigma(m)/phi(m) equals n.at n=23A070033