

A076507


3 people at a party are saying Hello to each other. Person " says Hello Hello. Person 3 counts the times Hello has been said and says Hello thrice that number. Person 1 says Hello equal to the sum of Hello's and then it is Person 2 again. This is how many Hello's are said.


1



2, 6, 8, 32, 144, 192, 768, 3456, 4608, 18432, 82944, 110592, 442368, 1990656, 2654208, 10616832, 47775744, 63700992, 254803968, 1146617856, 1528823808, 6115295232, 27518828544, 3669171392, 146767085568, 660451885056
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..26.
Index entries for linear recurrences with constant coefficients, signature (0,0,24).


FORMULA

G.f.: 2*x*(1x)*(1+4*x+8*x^2)/(124*x^3). [Colin Barker, Jun 07 2012]


PROG

(PARI) mod 3(n)=if (i%3==0, 3, i%3) s=2; for (i=3, 30, print1(s*mod 3(i), ", "); s=s+s*mod 3(i))


CROSSREFS

Cf. A076508.
Sequence in context: A096999 A019199 A094678 * A117542 A045653 A235320
Adjacent sequences: A076504 A076505 A076506 * A076508 A076509 A076510


KEYWORD

nonn,easy


AUTHOR

Jon Perry, Oct 15 2002


EXTENSIONS

a(16) corrected by Colin Barker, Jun 07 2012


STATUS

approved



