

A076507


Three people (P1, P2, P3) are in a circle and are saying Hello to each other. They start with P2 saying "Hello, Hello". Thereafter Pn says "Hello" for n times the total number of Hello's so far.


1



2, 6, 8, 32, 144, 192, 768, 3456, 4608, 18432, 82944, 110592, 442368, 1990656, 2654208, 10616832, 47775744, 63700992, 254803968, 1146617856, 1528823808, 6115295232, 27518828544, 36691771392, 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]


MATHEMATICA

LinearRecurrence[{0, 0, 24}, {2, 6, 8, 32}, 30] (* Harvey P. Dale, Sep 10 2021 *)


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
Better definition and corrected value for a(24) from Sean A. Irvine, May 19 2019


STATUS

approved



