21668

Appears in sequences

• Number of slanted n X 4 (i=1..n) X (j=i..4+i-1) 1..4 arrays with all 1s connected, all 2s connected, all 3s connected, all 4s connected, 1 in the upper left corner, 2 in the upper right corner, 3 in the lower left corner, 4 in the lower right corner, and with no element having more than 3 neighbors with the same value.at n=8A165381
• Absolute discriminants of complex quadratic fields with 3-class rank 2.at n=25A242862
• Absolute discriminants of complex quadratic fields with 3-class group of elementary abelian type (3,3) of rank 2.at n=16A242863
• Absolute discriminants of complex quadratic fields with 3-class group of type (3,3) and Hilbert 3-class field tower of exact length 3, except for the cases mentioned in the COMMENTS.at n=5A242878
• Minimal absolute discriminants a(n) of complex quadratic fields with 3-class group of type (3,3), 3-principalization type H.4 (2122), second 3-class group G of even nilpotency class cl(G)=2(n+3), and 3-class tower of unknown length at least 3.at n=0A247694
• Total length squared of longest runs of 1's in all bitstrings of length n.at n=10A334833
• Consecutive states of the linear congruential pseudo-random number generator (1291*s + 4621) mod 21870 when started at s=1.at n=7A385337