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A147677
Subtract 5, add 8, repeat.
2
7, 2, 10, 5, 13, 8, 16, 11, 19, 14, 22, 17, 25, 20, 28, 23, 31, 26, 34, 29, 37, 32, 40, 35, 43, 38, 46, 41, 49, 44, 52, 47, 55, 50, 58, 53, 61, 56, 64, 59, 67, 62, 70, 65, 73, 68, 76, 71, 79, 74, 82, 77, 85, 80, 88, 83, 91, 86, 94, 89, 97, 92, 100, 95, 103, 98, 106, 101, 109
OFFSET
1,1
COMMENTS
A147675-A147678 are from a quiz that someone asked me to help them with.
FORMULA
From Zak Seidov, Apr 22 2009: (Start)
a(n) = a(n-2) + 3.
a(n) = (1/4)*(6*n + 9 - 13*(-1)^n). (End)
From R. J. Mathar, Apr 22 2009: (Start)
a(n) = a(n-1) + a(n-2) - a(n-3) = 3*n/2 + 9/4 + 13*(-1)^(n+1)/4.
G.f.: x*(7-5*x+x^2)/((1+x)*(x-1)^2). (End)
MATHEMATICA
LinearRecurrence[{1, 1, -1}, {7, 2, 10}, 80] (* Harvey P. Dale, Jan 16 2015 *)
CROSSREFS
Sequence in context: A246948 A364899 A248283 * A090243 A216150 A145338
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Apr 21 2009
EXTENSIONS
More terms from Zak Seidov and R. J. Mathar, Apr 22 2009
STATUS
approved