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A137807
Final digit of prime(n)^2.
3
4, 9, 5, 9, 1, 9, 9, 1, 9, 1, 1, 9, 1, 9, 9, 9, 1, 1, 9, 1, 9, 1, 9, 1, 9, 1, 9, 9, 1, 9, 9, 1, 9, 1, 1, 1, 9, 9, 9, 9, 1, 1, 1, 9, 9, 1, 1, 9, 9, 1, 9, 1, 1, 1, 9, 9, 1, 1, 9, 1, 9, 9, 9, 1, 9, 9, 1, 9, 9, 1, 9, 1, 9, 9, 1, 9, 1, 9, 1, 1, 1, 1, 1, 9, 1, 9, 1, 9, 1, 9, 9, 1, 9, 1, 1, 9, 1, 1, 9, 1, 9, 9, 9, 1, 1
OFFSET
1,1
COMMENTS
Euler and Sadek ask whether the sequence, interpreted as the decimal expansion N = 0.49591..., is rational or irrational. - Charles R Greathouse IV, Apr 19 2010
REFERENCES
R. Euler and J. Sadek, A number that gives the unit digit of n^n. Journal of Recreational Mathematics, 29:3 (1998), pp. 203-204. [From Charles R Greathouse IV, Apr 19 2010]
FORMULA
a(n) = A010879(A001248(n)). - R. J. Mathar, May 03 2008
MAPLE
A001248 := proc(n) ithprime(n)^2 ; end: A010879 := proc(n) n mod 10 ; end: A137807 := proc(n) A010879(A001248(n)) ; end: seq(A137807(n), n=1..140) ; # R. J. Mathar, May 03 2008
MATHEMATICA
Mod[Prime[Range[110]]^2, 10] (* Harvey P. Dale, Jan 20 2022 *)
CROSSREFS
Sequence in context: A242610 A292484 A197418 * A163103 A019688 A365725
KEYWORD
nonn,base
AUTHOR
Paul Curtz, Apr 29 2008
EXTENSIONS
More terms from R. J. Mathar, May 03 2008
STATUS
approved