52303

Appears in sequences

• a(n) = Sum{a(k): k=0,1,2,...,n-4,n-2,n-1}; a(n-3) is not a summand; initial terms are 0,1,4.at n=18A049860
• Number of zero-sum -n..n arrays of 4 elements with first through third differences also in -n..n.at n=40A202512
• Numbers k such that 9*R_(k+2) - 7*10^k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=18A257037