75857

Appears in sequences

• a(n) = 1^n + 7^n + 9^n.at n=5A074524
• a(1)=1; a(2)=2; a(3)=3; a(n) = Sum_{k=3..n-1} (a(k) + a(k-1) + a(k-2)).at n=13A078344
• a(n) = Sum_{k=0..n} (-1)^k*A345652(k)*Stirling1(n, k).at n=11A350759
• a(n) = coefficient of x^n in Sum_{n>=0} x^n/(1 - x*C(x)^n), where C(x) = 1/(1 - x*C(x)) is a g.f. of the Catalan numbers (A000108).at n=11A357220
• Integers in Ulam's spiral for which the numbers around them form a square whose four corners are all prime numbers.at n=29A383596