27995

Appears in sequences

• Number of twin primes < 2^n.at n=21A033843
• Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (-1, 1), (0, 1), (1, -1), (1, 1)}.at n=9A151440
• Eigensequence for the Gould sequence triangle (with general term A001316(n-k) if k<=n, 0 otherwise).at n=12A185696
• Number of (n+5) X 10 0..1 matrices with each 6 X 6 subblock idempotent.at n=11A224574
• Numbers divisible by prime(d) for each digit d in their base-6 representation, none of which may be zero.at n=44A256876
• a(n) is the length of stage n in A137843.at n=14A291753