18912

Appears in sequences

• a(n) = prime(n)*(prime(n-1)-1)/2.at n=42A014302
• Numbers k such that sopf(k) = sopf(k+2), where sopf(k) = A008472(k).at n=17A063968
• Starting positions of strings of three 4's in the decimal expansion of Pi.at n=14A083615
• Average of twin-prime pairs for pairs that are expressible as the sum of two triangular numbers.at n=34A117313
• Number of slanted nX7 (i=1..n)X(j=i..7+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=1A165384
• Number of slanted 3 X n (i=1..3) X (j=i..n+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=5A165395
• Number of ordered triples (w,x,y) with all terms in {-n,...-1,1,...,n} and -2<=w+x+y<=2.at n=36A211616
• Number of (w,x,y) with all terms in {0,...,n} and the numbers w,x,y,|w-x|,|x-y| distinct.at n=29A213490
• a(n) = Sum_{i=0..n} Sum_{j=0..n} (i XOR j), where XOR is the binary logical exclusive-or operator.at n=32A224923
• Expansion of ( f(-q)^12 + 22 * q * f(-q)^6 * f(-q^5)^6 + 125 * q^2 * f(-q^5)^12 ) / (f(-q) * f(-q^5))^2 in powers of q where f() is a Ramanujan theta function.at n=12A235870
• Number of partitions of n such that the number of parts having multiplicity >1 is not a part and the number of distinct parts is a part.at n=47A241410
• Expansion of (1-sqrt(1-8*x-8*x^2))/(4*x).at n=6A290147
• Total volume of the family of rectangular prisms with dimensions p, q, and |q - p| where p divides q, n = p + q and p < q.at n=43A303479
• a(n) = 3*(3*n+1)*(9*n+8)/2.at n=21A304504
• Triangle read by rows: T(n,k) is the number of rooted ordered trees with node weights summing to n, where the root has weight 0, all internal nodes have weight 1, and leaf nodes have weights in {1,...,k}.at n=50A384685
• Numbers whose binary expansion consists of alternating runs of 1's and 0's where each run of 0's is exactly one longer than the preceding run of 1's, and the expansion ends with a 0-run.at n=37A387269