40136

Appears in sequences

• Numbers k such that k*Sum_{d|k} 1/sigma(d) is an integer.at n=24A069166
• Smallest multiple of the n-th prime beginning with n.at n=39A078209
• Number of permutations of 4 indistinguishable copies of 1..n with exactly 2 adjacent element pairs in decreasing order.at n=3A151640
• Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(4*n+1,i) * binomial(k+4-i,4)^n, 0 <= k <= 4*(n-1).at n=17A236463
• Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(4*n+1,i) * binomial(k+4-i,4)^n, 0 <= k <= 4*(n-1).at n=25A236463
• Triangle in which the g.f. for row n is (1-x)^(4*n+1) * Sum_{j>=0} binomial(n+j-1,j)^4 * x^j, read by rows of k=0..3*n terms.at n=24A262014
• Triangle in which the g.f. for row n is (1-x)^(4*n+1) * Sum_{j>=0} binomial(n+j-1,j)^4 * x^j, read by rows of k=0..3*n terms.at n=32A262014
• Number of rucksack compositions of n: every distinct partial run has a different sum.at n=19A354580
• Draw a regular n-gon and the enclosing circle, then for each pair of vertices X, Y, draw a circle with diameter XY; the union of these figures is the graph H_n; sequence gives number of regions in H_n.at n=22A370978
• Let p = A002145(n) be the n-th prime == 3 (mod 4); a(n) is the multiplicative order of 2+-i modulo p in Gaussian integers.at n=35A385165