18160

Appears in sequences

• Composite numbers k such that k!/k# - 1 is prime, where k# = primorial numbers A034386.at n=26A049421
• Numbers k such that k^6 == 1 (mod 7^5).at n=7A056103
• Write the numbers from 1 to n^2 in a spiraling square; a(n) is the total of the sums of the two diagonals.at n=24A059924
• Least positive k such that k * Z^n + 1 is prime, where Z = 10^100+267, the first prime greater than a googol.at n=32A108344
• Numbers k such that k * Fibonacci(k) + 1 is prime.at n=39A134313
• Numbers k such that k!/k#-1 is prime, where k# is the primorial function (A034386).at n=31A140293
• Number of line segments connecting exactly 5 points in an n x n grid of points.at n=30A177721
• Fibonacci-Collatz sequence: a(1)=0, a(2)=1; for n>2, let fib=a(n-1)+a(n-2); if fib is odd then a(n)=3*fib+1 else a(n)=fib/2.at n=15A181717
• Number of n X 2 0..3 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards.at n=36A201975
• Number of (n+2) X 4 binary arrays avoiding patterns 001 and 000 in rows and columns.at n=2A202595
• Number of (n+2)X5 binary arrays avoiding patterns 001 and 000 in rows and columns.at n=1A202596
• T(n,k)=Number of (n+2)X(k+2) binary arrays avoiding patterns 001 and 000 in rows and columns.at n=7A202601
• T(n,k)=Number of (n+2)X(k+2) binary arrays avoiding patterns 001 and 000 in rows and columns.at n=8A202601
• Number T(n,k) of squares of size k^2 in all tilings of an n X n square using integer-sided square tiles; triangle T(n,k), n >= 1, 1 <= k <= n, read by rows.at n=24A226936
• Number of partitions of n having an ordering of parts in which no parts of equal parity are adjacent and the first and last terms have the same parity.at n=48A239833
• Triangle read by rows: the multiset transform of the balanced binary Lyndon words (A022553).at n=68A289978
• Numbers k such that Bernoulli number B_{k} has denominator 230010.at n=5A295593
• Starts of runs of 3 consecutive Pell-Niven numbers (A352320).at n=14A352322
• Infinite square array, where row r >= 0 is the orbit of r under the map A380873: concatenate(sum of digits, product of digits).at n=30A380872
• Infinite square array, where row r >= 0 is the orbit of r under the map A380873: concatenate(sum of digits, product of digits).at n=40A380872