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A030127 Term at which n-Somos sequence first becomes nonintegral. 2
17, 19, 20, 22, 24, 27, 28, 30, 33, 34, 36, 39, 41, 42, 44, 46, 48, 51, 52, 55, 56, 58, 60, 62, 65, 66, 68, 70, 72, 75, 76, 78, 81, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 107, 108, 110, 112, 114, 116, 118, 120, 123, 124, 126, 129, 130, 132, 134, 136, 138 (list; graph; refs; listen; history; text; internal format)
OFFSET
8,1
COMMENTS
A101591 lists the positions of the odd terms. - Paul D. Hanna, Dec 08 2004
Conjecture: for even terms, a(n) = 2*n, else a(n) = 2*n+1 when n is in A101591. - Paul D. Hanna, Dec 08 2004
There does not seem to be a published proof that a(n) is defined for all n>=8. - Michael Somos, Jul 19 2014
LINKS
Ralph H. Buchholz and Randall L. Rathbun, An infinite set of Heron triangles with two rational medians, The American Mathematical Monthly, Vol. 104, No. 2 (Feb., 1997), pp. 107-115.
Harini Desiraju and Brady Haran, The Troublemaker Number, Numberphile video (2022).
David Gale, The strange and surprising saga of the Somos sequences, Math. Intelligencer 13(1) (1991), pp. 40-42.
J. L. Malouf, An integer sequence from a rational recursion, Discr. Math. 110 (1992), 257-261.
R. M. Robinson, Periodicity of Somos sequences, Proc. Amer. Math. Soc., 116 (1992), 613-619.
Eric Weisstein's World of Mathematics, Somos Sequence.
CROSSREFS
Cf. A101591.
Sequence in context: A156656 A130808 A194389 * A115849 A230634 A354880
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Paul D. Hanna, Dec 08 2004
STATUS
approved

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)