19493

Appears in sequences

• Numbers n such that sigma(n)^2 - phi(n)^2 is a perfect square.at n=39A057654
• Number of permutations of length n which avoid the patterns 231, 3214, 4312.at n=13A116712
• Table T(n,k) by antidiagonals. T(n,k) is the number of primitive (=aperiodic) k-ary words (n,k >= 1) with length less than or equal to n which are earlier in lexicographic order than any other word derived by cyclic shifts of the alphabet.at n=61A143327
• a(n) = 54*n^2 - 1.at n=18A158656
• Number of toothpicks after n stages of 3-D toothpick structure defined in Comments.at n=30A170876
• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 494", based on the 5-celled von Neumann neighborhood.at n=7A272547
• Number of primitive (=aperiodic) 5-ary words with length less than or equal to n which are earlier in lexicographic order than any other word derived by cyclic shifts of the alphabet.at n=6A320089
• Number of integer partitions of n containing all of their distinct multiplicities.at n=45A325705
• Integers k such that Euler(k, 1) is an integer multiple of Bernoulli(k + 1, 1).at n=43A342320
• One-third of the total number of edges formed after n points have been placed in general position on each edge of a triangle (as in A365929).at n=11A389626