3878550

Appears in sequences

• Number of nX2 0..4 arrays with rows and columns lexicographically nondecreasing and no element equal to the number of horizontal and vertical neighbors equal to itself.at n=9A201723
• a(n) = Product_{d|n, d>1} prime(A318881(d)), where A318881(d) records the prime signature of A000010(d).at n=47A319344