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A068498
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Fibonacci numbers whose sum of decimal digits is greater than its index.
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2
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8, 89, 377, 987, 1597, 2584, 6765, 28657, 46368, 196418, 3524578, 5702887, 39088169, 63245986, 267914296, 4807526976, 7778742049, 139583862445, 591286729879, 17167680177565, 27777890035288, 1304969544928657, 5527939700884757, 8944394323791464
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OFFSET
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1,1
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COMMENTS
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4.5 log(phi)/log(10) = 0.94... < 1, so this sequence is probably finite. The last term appears to be a(224) = F_5832 = 2927...6784; if there is another term it is greater than 10^20000. - Charles R Greathouse IV, Nov 19 2010
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LINKS
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EXAMPLE
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F(11)=89 and 8+9=17 > 11, so 89 is the term of this sequence.
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MATHEMATICA
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Fibonacci[#]&/@Select[Range[100], Total[IntegerDigits[Fibonacci[#]]]>#&] (* Harvey P. Dale, Apr 14 2014 *)
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PROG
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(Haskell)
a068498 n = a068498_list !! (n-1)
a068498_list = f [0..] a000045_list where
f (u:us) (v:vs) = if u < a007953 v then v : f us vs else f us vs
(PARI) lista(nn) = {for(n=1, nn, if (sumdigits(f=fibonacci(n)) > n, print1(f, ", "))); } \\ Michel Marcus, Apr 15 2014
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CROSSREFS
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KEYWORD
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nice,nonn,base
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AUTHOR
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EXTENSIONS
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Haskell program and b-file corrected. Thanks to Harvey P. Dale. - Reinhard Zumkeller, Apr 15 2014
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STATUS
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approved
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