21631

Appears in sequences

• Main diagonal of array in A083140.at n=24A083141
• Sum of the squares of the first n squarefree numbers.at n=30A111715
• a(n) = 676*n - 1.at n=31A158393
• a(n) = 32*n^2 - 1.at n=25A158563
• a(n) is the smallest term m in A173978 for which A020639(2m-3) = prime(n), n > 1.at n=40A173980
• Number of distinct solutions of sum{i=1..4}(x(2i-1)*x(2i)) = 1 (mod n), with x() in 0..n-1.at n=8A180806
• Least number k having n representations as the sum of the minimal number of biquadrates A002377(k).at n=13A185673
• Number of (w,x,y) with all terms in {0,...,n} and |w-x|+|x-y|+|y-w| <= w+x+y.at n=30A213487
• Number of length n+2 0..4 arrays with no consecutive three elements summing to more than 4.at n=6A241610
• T(n,k)=Number of length n+2 0..k arrays with no consecutive three elements summing to more than k.at n=51A241619
• Number of length 7+2 0..n arrays with no consecutive three elements summing to more than n.at n=3A241622
• Numbers k such that hexagonal number H(k) is the sum of two consecutive hexagonal numbers.at n=3A251602
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 603", based on the 5-celled von Neumann neighborhood.at n=14A289882
• a(n) is the number of rooted binary trees with minimal Sackin index and n leaves.at n=74A299037
• Bases in which 13 is a unique-period prime.at n=32A306077
• Numbers of the form (k^2 - 2) / 2 where k - 1 and k + 1 are both odd composite numbers.at n=28A339480
• Sum of the legs of the unique primitive Pythagorean triple whose inradius is the n-th prime and whose short leg is an odd number.at n=26A382097