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A003143 a(2n) = [ 17*2^n /14 ], a(2n+1) = [ 12*2^n /7 ].
(Formerly M0570)
1
1, 1, 2, 3, 4, 6, 9, 13, 19, 27, 38, 54, 77, 109, 155, 219, 310, 438, 621, 877, 1243, 1755, 2486, 3510, 4973, 7021, 9947, 14043, 19894, 28086, 39789, 56173, 79579, 112347, 159158, 224694, 318317, 449389, 636635, 898779, 1273270, 1797558 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

REFERENCES

D. E. Knuth, The Art of Computer Programming. Addison-Wesley, Reading, MA, Vol. 3, p. 207.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=0..41.

_Simon Plouffe_, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

_Simon Plouffe_, 1031 Generating Functions and Conjectures, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992.

MAPLE

A003143:=(1+z**3-z**4+z**5-z**6+z**7)/((z-1)*(z**2-z+1)*(z**2+z+1)*(2*z**2-1)); [Conjectured (correctly) by Simon Plouffe in his 1992 dissertation.]

PROG

(PARI) a(n)=(17+7*(n%2))*2^(n\2)\14

CROSSREFS

Sequence in context: A017824 A094054 A001521 * A221718 A017983 A139077

Adjacent sequences:  A003140 A003141 A003142 * A003144 A003145 A003146

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Michael Somos, May 04 2000

STATUS

approved

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Last modified May 21 08:52 EDT 2013. Contains 225478 sequences.