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A047346
Numbers that are congruent to {1, 4} mod 7.
8
1, 4, 8, 11, 15, 18, 22, 25, 29, 32, 36, 39, 43, 46, 50, 53, 57, 60, 64, 67, 71, 74, 78, 81, 85, 88, 92, 95, 99, 102, 106, 109, 113, 116, 120, 123, 127, 130, 134, 137, 141, 144, 148, 151, 155, 158, 162, 165, 169, 172, 176, 179, 183, 186, 190, 193, 197, 200, 204, 207, 211, 214
OFFSET
1,2
FORMULA
a(n) = floor( (7n-5)/2 ). - Santi Spadaro, Jul 24 2001
G.f.: x*(1 + 3*x + 3*x^2) / ( (1+x)*(x-1)^2 ). - R. J. Mathar, Dec 04 2011
a(n) = 4n - 3 - floor(n/2). - Wesley Ivan Hurt, Oct 16 2013
E.g.f.: 3 + ((14*x - 11)*exp(x) - exp(-x))/4. - David Lovler, Sep 01 2022
MAPLE
A047346:=n->4*n-3-floor(n/2); seq(A047346(k), k=1..100); # Wesley Ivan Hurt, Oct 16 2013
MATHEMATICA
Table[4n-3-Floor[n/2], {n, 100}] (* Wesley Ivan Hurt, Oct 16 2013 *)
PROG
(PARI) a(n) = 4*n-n\2-3; \\ Altug Alkan, Sep 10 2016
CROSSREFS
Cf. A001106.
Sequence in context: A073302 A191105 A248232 * A198270 A214971 A081840
KEYWORD
nonn,easy
STATUS
approved