51526

Appears in sequences

• Main diagonal of number array A082105.at n=15A082106
• Kekulé numbers for certain benzenoids (see the Cyvin-Gutman book for details).at n=10A123351
• Coefficients of a recursive polynomial based on Chaitin's S expressions: a(0)=1; a(1)=x; a(2)=1; a(n)=vector(a(n-1)).reverse(a(n-1)).at n=56A176703