501748

Appears in sequences

• a(0)=1, a(1)=0, a(2)=1, a(n) = a(n-1) + a(n-2) + 3*a(n-3).at n=19A123102
• First occurrence of difference n between two consecutive terms of A000404. a(n) gives the upper term. The lower term is A355237.at n=31A355238