30250

Appears in sequences

• a(n) = n + n*(n-1)*(n-2)*(n-3)*(n-4).at n=10A001095
• a(n) = n^2*(n-1)^3/4.at n=11A019584
• a(n) = A063997(n)/4.at n=38A088406
• Partition number array, called M32(-5), related to A013988(n,m)= |S2(-5;n,m)| ( generalized Stirling triangle).at n=21A144268
• a(n) = n times the square of Fibonacci(n).at n=10A169630
• Triangle generated by T(n,k) = q^k*T(n-1, k) + T(n-1, k-1), with q=3.at n=17A176243
• Central element of a series of 5 successive nonsquarefree numbers.at n=18A188296
• Numbers of spanning trees of the antiprism graphs.at n=4A193127
• Number of (w,x,y,z) with all terms in {1,...,n} and w + x > 2y + 2z.at n=22A212564
• Number of (w,x,y,z) with all terms in {0,...,n} and w=[R/2], where R=max{w,x,y,z}-min{w,x,y,z} and [ ]=floor.at n=32A212758
• The sum of the totatives of n is a perfect cube.at n=36A237282
• Prime factorization representation of Stern polynomials B(n,x) with only the even powers of x present: a(n) = A247503(A260443(n)).at n=67A284553
• a(n) = A247503(A277324(n)).at n=33A284563
• a(n) = A247503(A277324(n)).at n=48A284563
• Numbers k with the property that there exists a positive integer multiplier M such that M times the sum of the digits of k, multiplied further by the reversal of this product, gives k.at n=34A305131
• If the decimal expansion of n is d_1 ... d_k, a(n) = Sum d_i!*binomial(10,d_i).at n=15A306958
• G.f. A(x) satisfies: 1 = Sum_{n>=0} (n+1)*(n+2)*(n+3)/3! * 4^n * ((1+x)^n - A(x))^n.at n=4A337757
• a(n) = n! * Sum_{d|n} d/(d! * (n/d)!).at n=8A370581
• Integers k such that k = Sum k/(p_i + j), where p_i are the prime factors of k (with multiplicity). Case j = 1.at n=27A380889
• Number of subsets of the first n twin primes (A001097) whose sum is a twin prime.at n=18A385571