

A002536


a(n) = 8*a(n2)  9*a(n4).
(Formerly M3783 N1540)


2



0, 1, 1, 5, 8, 31, 55, 203, 368, 1345, 2449, 8933, 16280, 59359, 108199, 394475, 719072, 2621569, 4778785, 17422277, 31758632, 115784095, 211059991, 769472267, 1402652240, 5113721281, 9321678001, 33984519845, 61949553848, 225852667231
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OFFSET

0,4


REFERENCES

Murat Sahin and Elif Tan, Conditional (strong) divisibility sequences, Fib. Q., 56 (No. 1, 2018), 1831.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
A. Tarn, Approximations to certain square roots and the series of numbers connected therewith, Mathematical Questions and Solutions from the Educational Times, 1 (1916), 812.


LINKS



FORMULA

G.f.: x(1+x3x^2)/(18x^2+9x^4). A002537(n)/a(n) converges to sqrt(7).  Mario Catalani (mario.catalani(AT)unito.it), Apr 24 2003


MAPLE

A002536:=z*(1z+3*z**2)/(18*z**2+9*z**4); [Conjectured by Simon Plouffe in his 1992 dissertation.]


MATHEMATICA

LinearRecurrence[{0, 8, 0, 9}, {0, 1, 1, 5}, 30] (* Harvey P. Dale, May 28 2012 *)


CROSSREFS



KEYWORD

nonn,easy


AUTHOR



EXTENSIONS



STATUS

approved



