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

1,2

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.

Links

Table of n, a(n) for n=1..17.

Formula

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

Example

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

Mathematica

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

Crossrefs

Cf. A098206, A070826, A019461.

Sequence in context: A110202 A110201 A045739 * A000899 A226013 A156705

Adjacent sequences: A098202 A098203 A098204 * A098206 A098207 A098208

Keyword

nonn

Author

Labos Elemer, Oct 19 2004

Status

approved