20435

Appears in sequences

• Numbers n such that phi(n-1) + phi(n+1) = phi(2n).at n=13A067701
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, 1), (0, 0, -1), (0, 1, -1), (1, 0, 0)}.at n=10A148337
• Number of (n+1)X(n+1) -5..5 symmetric matrices with every 2X2 subblock having sum zero and one, two or three distinct values.at n=7A211333
• a(n) = Sum_{k=0..n} (-1)^k * binomial(n, k) * q(k), where q(k) is A000009 (partitions into distinct parts).at n=20A293467
• Determinant of the pentadiagonal symmetric nXn Toeplitz Matrix with a=3, b=c=1.at n=11A360263
• First term of the n-th differences of the strict partition numbers. Inverse zero-based binomial transform of A000009.at n=20A380412