77973

Appears in sequences

• Number of binary strings of length n with no substrings equal to 0001 0011 or 1101.at n=21A164460
• Expansion of Sum_{i>=1} mu(i)^2*i*x^i/(1 - x^i) / Product_{j>=1} (1 - x^j), where mu() is the Moebius function (A008683).at n=27A281904