

A355492


a(n) = 7*3^n  2.


1



5, 19, 61, 187, 565, 1699, 5101, 15307, 45925, 137779, 413341, 1240027, 3720085, 11160259, 33480781, 100442347, 301327045, 903981139, 2711943421, 8135830267, 24407490805, 73222472419, 219667417261, 659002251787, 1977006755365, 5931020266099, 17793060798301, 53379182394907
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OFFSET

0,1


COMMENTS

Right ending points of the gaps in A171884. The left ending points are given in A198643.


LINKS



FORMULA

G.f.: (5x)/((1x)*(13*x)).
E.g.f.: 7*exp(3*x)  2*exp(x).


EXAMPLE

The numbers not appearing in A171884 are those in the range [5*3^k1, 7*3^k2] for some k; that is, [4, 5] U [14, 19] U [44, 61] U ...


PROG

(PARI) a(n)=7*3^n2


CROSSREFS



KEYWORD

nonn,easy


AUTHOR



STATUS

approved



