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A152445
a(0) = a(1) = 1. For n >= 2, a(n) = the smallest prime >= a(n-1)*a(n-2).
2
1, 1, 2, 2, 5, 11, 59, 653, 38543, 25168589, 970072925867, 24415366771173991757, 23684686279828682858246730078719, 578270302382209771209755703072864217352250067119367
OFFSET
0,3
MAPLE
A152445 := proc(n) option remember ; if n <= 1 then 1; else nextprime(procname(n-1)*procname(n-2)-1) ; fi; end: for n from 0 to 15 do printf("%d, ", A152445(n)) ; od; # R. J. Mathar, Dec 05 2008
MATHEMATICA
a = {1, 1, 2, 2}; Do[AppendTo[a, Prime[PrimePi[a[[ -1]]*a[[ -2]]] + 1]], {7}]; a (* Stefan Steinerberger, Dec 06 2008 *)
nxt[{a_, b_}]:={b, NextPrime[a*b-1]}; NestList[nxt, {1, 1}, 15][[All, 1]] (* Harvey P. Dale, Jun 30 2020 *)
CROSSREFS
Sequence in context: A153983 A262714 A058021 * A077182 A230090 A286465
KEYWORD
nonn
AUTHOR
Leroy Quet, Dec 04 2008
EXTENSIONS
Extended beyond a(7) by R. J. Mathar, Stefan Steinerberger and Ray Chandler, Dec 05 2008
STATUS
approved