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A002488
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a(n) = n^(n^n).
(Formerly M5031 N2171)
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26
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OFFSET
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-1,4
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COMMENTS
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Regardless of whether one sets 0^0=1 or 0^0=0 we have a(0)=0.
Number of digits in terms n>3: 155 (n=4), 2185 (n=5), 36306 (n=6), 695975 (n=7), 15151336 (n=8)
This sequence can also be written as H_4(n,3) in standard hyperoperation notation or as (n "up-arrow"(2) 3) in Knuth up-arrow notation. For more info on hyperoperations see A054871.
Next term in base 36 is 14PLKI42MDV1MT36I2RNAK3GINNT5VCX207HPUF9X0VJ6I1I7H29NU\ 12WLS3ULFV1YYABI94UA3WAUAMSXZ4SNWV27FYA36HQDJ4. - Alonso del Arte, Jul 01 2012
0^^3 = 0 since 0^^k = 1 for even k, 0 for odd k, k >= 0. - Daniel Forgues, May 18 2013
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REFERENCES
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N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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FORMULA
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a(n) = H_4(n,3);
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EXAMPLE
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a(3) = H_4(3,3) = 3^3^3 = 3^27 = 7625597484987.
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MAPLE
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MATHEMATICA
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PROG
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CROSSREFS
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KEYWORD
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sign,nice
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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