A211404 Numbers n such that the leading n digits of n^n in decimal form a prime or a probable prime.

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.

Links

Table of n, a(n) for n=1..6.

Mathematica

Select[Range[8, 1000], PrimeQ[FromDigits[Take[IntegerDigits[#^#], #]]] &] (* T. D. Noe, Feb 11 2013 *)

Crossrefs

Cf. A220453, A220454.

Sequence in context: A286612 A276963 A338413 * A297317 A224099 A220229

Adjacent sequences: A211401 A211402 A211403 * A211405 A211406 A211407

Keyword

nonn,base

Author

James G. Merickel, Feb 09 2013

Status

approved