23155

Appears in sequences

• a(n) = Sum_{m=1..n} Sum_{k=1..m} prime(k).at n=33A014148
• Pseudoprimes to base 21.at n=39A020149
• Number of subwords UHH...HD in all peakless Motzkin paths of length n+3, where U=(1,1), D=(1,-1) and H=(1,0).at n=11A089742
• Trajectory of 8 under iteration of the map k -> A087712(k).at n=22A144813
• Result of using the perfect squares as coefficients in an infinite polynomial series in x and then expressing this series as (1+a(1)x)(1+a(2)x^2)(1+a(3)x^3)...at n=15A147559
• Number of UH^jD's for some j>0, in all peakless Motzkin paths of length n (here U=(1,1), D=(1,-1) and H=(1,0); can be easily expressed using RNA secondary structure terminology).at n=14A187258
• Constant term of the reduction by x^2->x+1 of the polynomial p(n,x) defined at Comments.at n=10A193046
• A000136(n)/2.at n=9A213439
• Expansion of Sum_{i>=0} x^(2^i)/(1 - x^(2^i)) / Product_{j>=0} (1 - x^(2^j)).at n=53A281688
• Expansion of exp( Sum_{n>=1} -sigma_3(n)*x^n/n ) in powers of x.at n=17A283263
• a(n) = [x^n] ((x - 1)*(x + 1)*(2*x^2 - 1))/(2*x^4 + 4*x^3 - x^2 - 3*x + 1).at n=10A327993
• Expansion of e.g.f. exp( -(exp(x) - 1)^3 / 6 ).at n=9A354396