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A169687
a(n) = 3^n - 3*2^(n-2).
1
6, 21, 69, 219, 681, 2091, 6369, 19299, 58281, 175611, 528369, 1588179, 4770681, 14324331, 42997569, 129041859, 387223881, 1161868251, 3485997969, 10458780339, 31377913881, 94136887371, 282416953569, 847263443619, 2541815496681, 7625496821691, 22876591128369
OFFSET
2,1
LINKS
PROG
(Magma) [3^n-3*2^(n-2): n in [2..35]]; // Vincenzo Librandi, Jun 30 2011
CROSSREFS
Arises in the analysis of A169688.
Sequence in context: A364636 A318943 A200761 * A302448 A101904 A022814
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Apr 14 2010
STATUS
approved