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A093092
"Fibonacci in digits - up and down": start with a(1)=1, a(2)=1; repeatedly adjoin either the sum of the two previous terms (if that sum happens to be even) or else adjoin digits of the sum of previous two terms (if that sum happens to be odd).
2
1, 1, 2, 3, 5, 8, 1, 3, 9, 4, 12, 1, 3, 16, 1, 3, 4, 1, 9, 1, 7, 4, 7, 5, 10, 10, 8, 1, 1, 1, 1, 12, 1, 5, 20, 18, 9, 2, 2, 2, 1, 3, 1, 3, 6, 2, 5, 38, 2, 7, 1, 1, 4, 4, 3, 4, 4, 4, 9, 8, 7, 4, 3, 40, 9, 8, 2, 5, 8, 7, 7, 8, 8, 1, 3, 1, 7, 1, 5, 1, 1, 7, 4, 3, 4, 9, 1, 7, 10, 7, 1, 3, 1, 5, 14, 1, 5, 16, 9, 4
OFFSET
1,3
EXAMPLE
... a(6)=a(4)+a(5), a(7)=left digit of (a(5)+a(6)=5+8=1 3) as 13 is odd, a(8)=right digit of (a(5)+a(6)=5+8=1 3) as 13 is odd, a(11)=a(8)+a(9) as even ...
MATHEMATICA
a = {0, 1}; f[n_] := Block[{k = a[[n - 1]] + a[[n - 2]]}, If[ EvenQ[k], AppendTo[a, k], a = Join[a, IntegerDigits[k]] ]]; Do[ f[n], {n, 3, 100}]; a (* Robert G. Wilson v, Mar 27 2004 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Bodo Zinser, Mar 20 2004
STATUS
approved