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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.
1
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.
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
KEYWORD
nonn
AUTHOR
Labos Elemer, Oct 19 2004
STATUS
approved