451584

Appears in sequences

• Theta series of E_8 lattice with respect to deep hole.at n=29A004017
• Droll numbers: numbers > 1 whose sum of even prime factors equals the sum of odd prime factors.at n=25A019507
• Numbers k such that Sum_{i=1..k} gcd(k,i) divides Sum_{i=1..k} lcm(k,i).at n=18A072109
• Squares of second pentagonal numbers: a(n) = (1/4)*n^2*(3*n+1)^2.at n=21A100256
• Delannoy paths counted by number of weak peaks.at n=51A133214
• Squares appearing in A062064: a(n) = A062064(n) + A062064(n+1).at n=32A134537
• Numbers m such that m = s|t = phi(s)*sigma(t) for some numbers s and t, where "|" denotes concatenation.at n=6A159000
• Triangle read by rows: T(n,m) = A094310(n,m)*A120070(n+1,m), 1 <= m <= n.at n=32A165969
• Number of arrangements of n bishops such that every square of the board is controlled by at least one bishop.at n=9A182333
• Squares equal to the difference between two successive primes of the form n^2+1.at n=15A216330
• Cyclic quadrilateral numbers: numbers m = a*b*c*d such that the integers a,b,c,d are the sides of a cyclic quadrilateral whose area and circumradius are integers.at n=5A218431
• Irregular triangular array read by rows: T(n,k) is the number of 2-colored simple labeled graphs on n nodes that have exactly k edges, 0<=k<=A002620(n), n>=1.at n=61A241669
• a(n) = 2*5^n - (1+2i)^(2n) - (1-2i)^(2n) where i = sqrt(-1).at n=8A250102
• G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2*n} A200536(n,2*n-k)^2 * x^k] / A(x)^n * x^n/n ), where A200536(n,2*n-k) is the coefficient of x^k in (2+3*x+x^2)^n.at n=23A251689
• Number of (n+2)X(2+2) 0..1 arrays with no 3x3 subblock diagonal sum equal to the antidiagonal sum or central row sum less than the central column sum.at n=6A257355
• Number of (n+2)X(7+2) 0..1 arrays with no 3x3 subblock diagonal sum equal to the antidiagonal sum or central row sum less than the central column sum.at n=1A257360
• T(n,k) = Number of (n+2) X (k+2) 0..1 arrays with no 3 X 3 subblock diagonal sum equal to the antidiagonal sum or central row sum less than the central column sum.at n=29A257361
• Numbers such that (sum + product) of all their prime factors equals (sum + product) of all exponents in their prime factorization.at n=34A272818
• a(n) = Product_{d|n} (d*sigma(d)) where sigma(k) = the sum of the divisors of k (A000203).at n=20A324980
• a(n) = (24*n)^2.at n=28A325475