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A005510 a(n) = 1 + a(floor(n/2))*a(ceiling(n/2)) for n > 1, a(1) = 3.
(Formerly M2842)
0
3, 10, 31, 101, 311, 962, 3132, 10202, 31412, 96722, 299183, 925445, 3012985, 9809425, 31952665, 104080805, 320465225, 986713745, 3038231465, 9355145285, 28937578127, 89510467490, 276877411436, 856448448026, 2788351903326, 9078078610226, 29555650383626 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms are congruent to 3 mod 7.

REFERENCES

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=1..27.

MAPLE

a:= proc(n) option remember; `if`(n=1, 3,

      1+(t->a(t)*a(n-t))(iquo(n, 2)))

    end:

seq(a(n), n=1..30);  # Alois P. Heinz, Jul 04 2019

CROSSREFS

Cf. A005468, A005469.

Sequence in context: A214839 A114487 A017934 * A005725 A302287 A079522

Adjacent sequences:  A005507 A005508 A005509 * A005511 A005512 A005513

KEYWORD

nonn,easy

AUTHOR

Colin Mallows

STATUS

approved

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Last modified May 24 23:45 EDT 2020. Contains 334581 sequences. (Running on oeis4.)