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A258389
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a(n) = (n^(n+1)-(n-1)^n) + ((n+1)^n-n^(n-1)).
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2
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2, 14, 128, 1504, 21752, 374184, 7464368, 169402496, 4309519952, 121450640200, 3755499322808, 126409853754144, 4600799868451880, 180029930424249416, 7536568838736534752, 336087767194699956736, 15905186914751401828640, 796113699641442496367496
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OFFSET
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1,1
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LINKS
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FORMULA
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a(n) = (n^(n+1)-(n-1)^n) + ((n+1)^n-n^(n-1)) = A084363(n) + A178922(n).
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EXAMPLE
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For a(3) = (3^(3+1)-(3-1)^3) + ((3+1)^3-3^(3-1)) = (3^4 - 2^3) + (4^3 - 3^2) = 128.
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MATHEMATICA
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Array[#^(# + 1) - (# - 1)^# + ((# + 1)^# - #^(# - 1)) &, 20] (* Vincenzo Librandi, May 29 2015 *)
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PROG
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(Sidef)
func a(n) {
((n+1)**n - n**(n-1)) -
((n-1)**n - n**(n+1))
};
1.to(Math.inf).each { |n|
say a(n);
};
(Magma) [(n^(n+1)-(n-1)^n) + ((n+1)^n-n^(n-1)): n in [1..20]]; // Vincenzo Librandi, May 29 2015
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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