47172

Appears in sequences

• Sum{T(n-k,k)}, 0<=k<=[ n/2 ], where T is the array in A026374.at n=20A026385
• All 81 combinations of prefixing and following a(n) by a single digit are nonprime.at n=36A032734
• Composite numbers k such that all the decimal concatenations ik and ikj (i, j = 1...9) are also composite.at n=23A032737
• Concatenation of n, n+1, n+2 divided by 3.at n=14A074991
• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 390", based on the 5-celled von Neumann neighborhood.at n=8A271599