70186

Appears in sequences

• a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-1)*a(1) for n >= 4.at n=12A025262
• Number of words of length n in a simple grammar.at n=11A056010
• Recamán Fibonacci variation: a(1)=1; a(2)=2; for n > 2, a(n) = a(n-1)+a(n-2)-F(n) if that number is positive and not already in the sequence, otherwise a(n) = a(n-1)+a(n-2)+F(n) where F(n) denotes the n-th Fibonacci number.at n=29A079053
• Irregular array where the n-th row are the divisors, not occurring earlier in the sequence, of the sum of the terms in all previous rows. a(1)=2.at n=55A120576
• Number of regions in a "cross" of width 3 and height n (see Comments for definition).at n=23A331455