OFFSET
1,3
COMMENTS
All the terms in A046967 are of the form 2^k.
FORMULA
From Amiram Eldar, Oct 13 2024: (Start)
a(n) = floor(log_10(2) * A070826(n)). (End)
MATHEMATICA
a = {}; c = 2; Do[d = Length[IntegerDigits[c, 10]]; c = c^Prime[n]; AppendTo[a, d], {n, 2, 9}]; a
IntegerLength/@RecurrenceTable[{a[1]==2, a[n]==a[n-1]^Prime[n]}, a[n], {n, 9}] (* Harvey P. Dale, Jul 18 2011 *)
1 + Floor[Log10[2] * FoldList[Times, 1, Prime[Range[2, 20]]]] (* Amiram Eldar, Oct 12 2024 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Artur Jasinski, Nov 24 2007
EXTENSIONS
a(9) from Harvey P. Dale, Jul 18 2011
More terms from Amiram Eldar, Oct 12 2024
STATUS
approved