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A064236 Number of decimal digits in A001042. 2
1, 1, 1, 1, 2, 3, 5, 10, 19, 38, 76, 152, 303, 605, 1210, 2420, 4839, 9678, 19355, 38709, 77417, 154834, 309667, 619333, 1238665, 2477330, 4954660, 9909319, 19818638, 39637275, 79274549 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Table of n, a(n) for n=0..30.

MATHEMATICA

a[ 1 ] = 1; a[ 2 ] = 2; a[ n_ ] := a[ n ] = a[ n - 1 ]^2 - a[ n - 2 ]^2; Table[ Floor[ N[ Log[ 10, a[ n ] ], 36 ] ] + 1, {n, 1, 31} ]

IntegerLength[#]&/@(RecurrenceTable[{a[1]==1, a[2]==2, a[n]==a[n-1]^2- a[n-2]^2}, a, {n, 31}]) (* Harvey P. Dale, Dec 27 2013 *)

PROG

(PARI) a(n) = if(n<2, n+1, a(n-1)^2-a(n-2)^2); l(n) = ln=0; while(n, n=floor(n/10); ln++); return(ln); for(n=0, 21, print(l(a(n))))

(Haskell)

a064236 = length . show . a001042  -- Reinhard Zumkeller, Dec 16 2013

CROSSREFS

Sequence in context: A177874 A293353 A293328 * A245001 A007569 A054317

Adjacent sequences:  A064233 A064234 A064235 * A064237 A064238 A064239

KEYWORD

base,nonn

AUTHOR

Jason Earls, Sep 22 2001

EXTENSIONS

More terms from Robert G. Wilson v, Sep 24 2001

STATUS

approved

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Last modified February 24 07:30 EST 2018. Contains 299597 sequences. (Running on oeis4.)