20724

Appears in sequences

• a(n) = n*(3*n^2 - 1)/2.at n=24A004188
• s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = A001950 (upper Wythoff sequence).at n=31A025122
• Numbers k such that 2^k + 3 is prime.at n=34A057732
• a(n) = n^4 - n.at n=12A058895
• Numbers whose set of base 12 digits is {0,B}, where B base 12 = 11 base 10.at n=14A097258
• Expansion of x^2*(-3+4*x)/(1-x^3+x^4).at n=54A110061
• Primitive elements of A065607.at n=15A120692
• Elements of A065607 from primitive triples.at n=22A120693
• Values of y in solutions (x,y,z) to the Diophantine equation x^3-x^2+y^3-y^2=z^3-z^2, with 1<x<y<z arranged in order of increasing x.at n=20A138668
• 144*n^2 - n.at n=11A156635
• a(n) = 576*n^2 - 2*n.at n=5A158371
• a(n) = 144*n^2 - 12.at n=11A158543
• Quadruples (a,b,c,d) of the form ( n*(n^3-1), n^3-1, 2*n^3+1, n*(n^3+2) ).at n=44A204767
• A sum over partitions (q=12), see first comment.at n=4A221580
• Number of (n+3) X 8 0..1 matrices with each 4 X 4 subblock idempotent.at n=15A224565
• Number of (n+1) X (2+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).at n=3A234221
• Number of (n+1) X (4+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).at n=1A234223
• T(n,k) is the number of (n+1) X (k+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).at n=11A234227
• T(n,k) is the number of (n+1) X (k+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3 (constant-stress 1 X 1 tilings).at n=13A234227
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 1006", based on the 5-celled von Neumann neighborhood.at n=35A273861