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A128897
a(n) = ((2n)^(2n-1)+1)/(2n+1).
0
1, 13, 1111, 233017, 90909091, 57154490053, 52914318216943, 67818912035696881, 115047976828352449051, 249660952380952380952381, 674758650917429955329341351, 2222892961417140207415135788073
OFFSET
1,2
FORMULA
a(n) = ((2n)^(2n-1)+1)/(2n+1). a(n) = A083062(2n-1).
CROSSREFS
Cf. A083062 ((n+1)^n/(n+2) - (-1)^n/(n+2)).
Sequence in context: A264249 A195890 A195520 * A201265 A221390 A226095
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Apr 20 2007
STATUS
approved