173127

Appears in sequences

• Triangle T, read by rows, where column k equals column k of T^(k+1) shift down 1 row, with T(n,n)=T(n+1,n)=1 for n>=0.at n=57A121391
• Column 2 of triangle A121391, where column k of T=A121391 equals column k of T^(k+1) shift down 1 row.at n=8A121393