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A211404
Numbers n such that the leading n digits of n^n in decimal form a prime or a probable prime.
0
65, 603, 12208, 18803, 18841, 25207
OFFSET
1,1
COMMENTS
Search completed through n=28900. a(1)=65 occurs in A220454, the 65-digit right truncation of 65^65 being the only prime right truncation for 65 and no first right truncation for a smaller number than 65 being 65 or more digits.
MATHEMATICA
Select[Range[8, 1000], PrimeQ[FromDigits[Take[IntegerDigits[#^#], #]]] &] (* T. D. Noe, Feb 11 2013 *)
CROSSREFS
Sequence in context: A286612 A276963 A338413 * A297317 A224099 A220229
KEYWORD
nonn,base
AUTHOR
James G. Merickel, Feb 09 2013
STATUS
approved