22521

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 100.at n=33A031598
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 86 ones.at n=28A031854
• Numerator of the generalized harmonic number H(n,5,1).at n=5A075137
• Integer part of Gauss's Arithmetic-Geometric Mean M(1,n^4).at n=20A127760
• 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, 0, 0), (-1, 1, 1), (1, -1, 0), (1, 0, -1), (1, 0, 0)}.at n=9A148747
• Integers that reach the (47360, 29127) cycle described in A234534, after iterations of numerator(sigma(n)/n) = A017665(n).at n=0A249614
• Number of (n+1) X (7+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.at n=8A250655
• Number of (n+2) X (7+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 1 3 6 or 7.at n=4A252304
• Number of (5+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7.at n=6A252310
• Numbers n such that the decimal number concat(6,n) is a square.at n=33A273361
• Expansion of Product_{n>=1} (1 - x^(7*n))^7/(1 - x^n)^8 in powers of x.at n=7A277958
• Number of ways to tile a 3 X n strip with squares and P-shaped heptominoes.at n=12A352789
• Numbers k such that k and k+2 are both A000120-perfect numbers (A175522).at n=26A360639