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A109070
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Number of digits in numbers appearing in A108225.
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1
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1, 1, 1, 1, 2, 2, 4, 7, 13, 25, 50, 99, 196, 392, 783, 1566, 3131, 6261, 12521, 25042, 50084, 100166, 200332, 400663, 801325, 1602649, 3205298, 6410595, 12821190, 25642379, 51284758
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,5
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COMMENTS
| Starting with a(14)=783, a(n) = 2*a(n-1) - (1 or 0).
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EXAMPLE
| A109070(10)=50 because A108225(10)=16217557574922386301420536972254869595782763547562 has 50 digits.
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MATHEMATICA
| nxt[{a_, b_}]:={b, ((a+b)(b-a+1))/2}; Join[{1}, IntegerLength/@ Transpose[ NestList[nxt, {0, 2}, 31]][[2]]] (* From Harvey P. Dale, Feb 14 2012 *)
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CROSSREFS
| Cf. A108225.
Sequence in context: A095325 A153970 A067953 * A169973 A049868 A120363
Adjacent sequences: A109067 A109068 A109069 * A109071 A109072 A109073
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KEYWORD
| base,nonn,changed
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AUTHOR
| Zak Seidov (zakseidov(AT)yahoo.com), Jun 18 2005
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