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A199213
a(n) = (3*5^n+1)/2.
2
2, 8, 38, 188, 938, 4688, 23438, 117188, 585938, 2929688, 14648438, 73242188, 366210938, 1831054688, 9155273438, 45776367188, 228881835938, 1144409179688, 5722045898438, 28610229492188, 143051147460938, 715255737304688
OFFSET
0,1
FORMULA
a(n) = 2*A083065(n).
a(n) = 5*a(n-1)-2.
a(n) = 6*a(n-1)-5*a(n-2).
G.f.: 2*(1-2*x)/((1-x)*(1-5*x)). - Bruno Berselli, Nov 04 2011
PROG
(Magma) [(3*5^n+1)/2: n in [0..30]];
CROSSREFS
Cf. A083065.
Sequence in context: A192529 A155609 A220542 * A002003 A123164 A264229
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 04 2011
STATUS
approved