OFFSET
1,2
COMMENTS
A139244(n-1) = ceiling(c^(2^n)).
The digit 4 appears for the first time only at position n=53, making it the last one to appear in the sequence.
LINKS
A. V. Aho and N. J. A. Sloane, Some doubly exponential sequences, The Fibonacci Quarterly, 11 (1973), 429-437.
EXAMPLE
1.96689176179017636533350572... .
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Chayim Lowen, Jul 22 2015
STATUS
approved