A098205 A first order iteration: n-th term is obtained from (n-1)-th by adding n-th prime and then multiplying by the n-th prime; initial value is 0.

0, 9, 70, 539, 6050, 78819, 1340212, 25464389, 585681476, 16984763645, 526527673956, 19481523937741, 798742481449062, 34345926702311515, 1614258555008643414, 85555703415458103751, 5047786501512028124790

Offset: 1

Author

Labos Elemer, Oct 19 2004

Keywords

• nonn

Comments

Difference between sequences generated by this recursion with iv=1[A098206] and iv=0[A098205] provides A070826, i.e. half of n-th primorial number. Analogous recursion is A019461.

Examples

			a[4]=(70+p[4])*p[4]=(70+7)*7=490+49=539=
		

Crossrefs

Cf. A098206, A070826, A019461.

Programs

Mathematica

f[x_] :=(f[x-1]+Prime[x])*Prime[x];f[1]=0; Table[f[w], {w, 1, 25}]

Formula

a[n]=(a[n-1]+p[n])*p[n], a[0]=0.