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A083081
First superdiagonal of number array A083075.
3
1, 13, 229, 4921, 128841, 4022341, 146450893, 6103787761, 286833509137, 15011892880381, 866190689012661, 54637591044108073, 3740820141248285785, 276304073198956644661, 21900911192388373534621
OFFSET
1,2
LINKS
FORMULA
a(n) = ((n-1)*(2n+1)^n + 1)/n.
PROG
(Magma) [((n-1)*(2*n+1)^n+1)/n: n in [1..20]]; // Vincenzo Librandi, Nov 12 2011
CROSSREFS
Sequence in context: A223548 A201706 A176722 * A083306 A114755 A142610
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Apr 23 2003
STATUS
approved