19502

Appears in sequences

• a(n) = prime(n)*(prime(n-1)-1)/2.at n=43A014302
• Numbers k such that k + sum of its prime factors = (k+1) + sum of its prime factors.at n=26A020700
• First differences of (n+1)^6-n^6 (A022522).at n=4A069473
• Number of positions that are exactly n moves from the starting position in the Rubik's UFO puzzle.at n=6A079819
• Number of functions f:{1,2,...,n}->{1,2,...,n} such that Im(f) contain two fixed elements.at n=4A126778
• Pell numbers A000129 without last digit.at n=11A131727
• Triangular array T(n,k): functions f:{1,2,...,n}-> {1,2,...,n} such that each of k fixed (but arbitrary) elements are in the image of f.at n=23A174551
• Number of ordered triples (w,x,y) with all terms in {-n,...,-1,1,...,n} and w+3x+3y>0.at n=17A211625
• Number of (w,x,y,z) with all terms in {0,...,n} and odd range.at n=13A212890
• The number of permutations of length n sortable by 2 reversals.at n=19A228396
• Number of ordered n-tuples of positive integers, whose minimum is 0 and maximum is 5.at n=5A245020
• Numbers k such that 5*10^k - 43 is prime.at n=24A281513
• Smallest integer that is the sum of a prime and the square of a prime in n or more ways.at n=23A381333
• Smallest integer that is the sum of a prime and the square of a prime in exactly n ways.at n=23A381334
• Triangle read by rows: T(n,k) is the number of endofunctions on [n] where the difference between the smallest and largest values in the image of the function is k, 0 <= k < n.at n=20A391488
• Triangle read by rows: T(n,k) = Sum_{j=0..k} (-1)^(k-j) * binomial(k,j) * (4+j)^n.at n=23A391633