42042

Appears in sequences

• a(n) = (2n+4)!/(4!*n!*(n+1)!).at n=5A002803
• Number of prime palindromes with n digits.at n=10A016115
• a(n) = (n+1)*binomial(n+1,6).at n=8A027766
• a(n) = (n+1)*binomial(n+1,8).at n=6A027768
• a(n) is the number of prime palindromes with 2n+1 digits.at n=5A040025
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= n/3.at n=37A048002
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n-1)/3.at n=37A048015
• Number of nonempty subsets of {1,2,...,n} in which exactly 5/6 of the elements are <= (n-2)/3.at n=37A048026
• Triangular array of Motzkin polynomial coefficients.at n=60A055151
• Triangle (0 <= k <= n) read by rows: T(n, k) is the number of Schröder paths from (0,0) to (2n,0) having k peaks.at n=49A060693
• Triangle read by rows: T(n,k) = C(n+k,n)*C(n,k)/(k+1), for n >= 0, k = 0..n.at n=50A088617
• a(n) = 14*binomial(n,8).at n=14A088625
• a(n) = 42*binomial(n,10).at n=14A088626
• Triangle read by rows: T(n,k)=(1/2)*C(n+k,k)*C(n,n-k).at n=33A092370
• Number triangle T(n,k) = binomial(n,k)*binomial(2n,n-k).at n=30A110608
• Non-palindromes in A110751; that is, non-palindromic numbers n such that n and R(n) have the same prime divisors, where R(n) = digit reversal of n.at n=10A110819
• Row sums of a Pascal-Thue-Morse triangle.at n=17A114226
• a(n) = (n+1)*(n+2)^2*(n+3)*(n+4)*(3*n+5)/240.at n=10A114243
• Number of 7-dimensional partitions of n up to conjugacy.at n=16A119342
• Number of permutations of 0..floor((n*3-1)/2) on even squares of an n X 3 array such that each row and column of even squares is increasing.at n=8A215287