194480

Appears in sequences

• a(n) = (2n+3)!/(n!*(n+2)!).at n=7A000917
• a(n+1) = a(n)/n if n|a(n) else a(n)*n, a(1) = 1.at n=18A008336
• a(n) = Sum_{j=0..n} A047072(j, n-j).at n=20A047073
• Expansion of (1+6x)/(1-x)^10.at n=9A055994
• Positive numbers which are one less than a perfect square that is also another power.at n=27A062965
• LCM of terms in Collatz (3x+1) function initiated at n.at n=10A087226
• LCM of terms in Collatz (3x+1) function initiated at n.at n=21A087226
• a(n) = binomial(n+3,3)*binomial(n+7,3).at n=10A104474
• Numbers k such that both k and k + 1 are logarithmically smooth.at n=13A116486
• a(n) = n^4 - 1.at n=20A123865
• Positive integers k such that all the distinct primes that divide k or k+1 are members of a set of consecutive primes. In other words, k is included if and only if k*(k+1) is contained in sequence A073491.at n=26A141399
• a(n) = 4*C(2n,n) - 3*0^n.at n=9A146534
• Number of valleys in all left factors of Dyck paths of length n. A valley is a (1,-1)-step followed by a (1,1)-step.at n=18A191522
• Number of turns in all left factors of Dyck paths of length n.at n=17A191527
• Order of Fibonacci group F(n,4) (or 0 if the group is infinite).at n=20A202626
• a(n) = (n!*m)/(m!*(m+1)!) where m = floor(n/2).at n=17A237884
• a(n) = 4*(2*n)! / (n!)^2.at n=9A240530
• a(n) = Fibonacci(n)^4-1.at n=7A244855
• The largest prime factor of n*(n+1) equals 17. (Related to the abc conjecture.)at n=38A252492
• Number of permutations of length n such that numbers at odd positions are monotone and numbers at even positions are also monotone.at n=18A257546