A093096 Start with a(1) = a(2) = 3; then apply the rule of A093094.
3, 3, 9, 2, 7, 1, 8, 1, 4, 7, 8, 8, 4, 2, 8, 5, 6, 6, 4, 3, 2, 8, 1, 6, 4, 0, 3, 0, 3, 6, 2, 4, 1, 2, 6, 1, 6, 8, 6, 2, 4, 0, 0, 0, 0, 1, 8, 1, 2, 8, 4, 2, 1, 2, 6, 6, 4, 8, 4, 8, 1, 2, 8, 0, 0, 0, 0, 0, 8, 8, 2, 1, 6, 3, 2, 8, 2, 2, 1, 2, 3, 6, 2, 4, 3, 2, 3, 2, 3, 2, 8, 2, 1, 6, 0, 0, 0, 0, 0, 0, 6, 4, 1, 6, 2
Offset: 1
Examples
a(3)=a(1)*a(2), a(4)=first digit of (a(2)*a(3)), a(5)=2nd digit of (a(2)*a(3)), a(6)=first digit of (a(3)*a(4)), a(7)=2nd digit of (a(3)*a(4))
References
- Hugo Steinhaus, Studentenfutter, Urania, Leipzig 1991, #1.
Links
- Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
Programs
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Haskell
a093096 n = a093096_list !! (n-1) a093096_list = f [3,3] where f (u : vs@(v : _)) = u : f (vs ++ if w < 10 then [w] else uncurry ((. return) . (:)) $ divMod w 10) where w = u * v -- Reinhard Zumkeller, Aug 13 2013
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Mathematica
Fold[Join[#, IntegerDigits[Times @@ #[[#2;; #2+1]]]] &, {3, 3}, Range[100]] (* Paolo Xausa, Aug 18 2025 *)
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Python
from itertools import islice from collections import deque def agen(): # generator of terms a = deque([3, 3]) while True: a.extend(list(map(int, str(a[0]*a[1])))) yield a.popleft() print(list(islice(agen(), 105))) # Michael S. Branicky, Aug 18 2025
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