21769

Appears in sequences

• a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = A000201 (lower Wythoff sequence).at n=44A025118
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 80 ones.at n=23A031848
• a(0) = 12, after which, if (2*a(n-1)) - 1 = product_{k >= 1} (p_k)^(c_k) then a(n) = product_{k >= 1} (p_{k-1})^(c_k), where p_k indicates the k-th prime, A000040(k).at n=36A246343
• Rectangular array A read by upward antidiagonals in which the entry in row n and column k is defined by A(n,k) = A254067(n,k) - A257499(n,k), n,k >= 1.at n=46A254131
• Number of n X n 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 3 neighboring 1's.at n=4A296389
• Number of nX5 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 3 neighboring 1s.at n=4A296393
• T(n,k)=Number of nXk 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 3 neighboring 1s.at n=40A296396
• Records in A361321.at n=29A361325
• Consecutive states of the linear congruential pseudo-random number generator (10924*s+11830) mod (2^15+1) when started at s=1.at n=24A384150