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A247094 Integers of the form (2^k + 1)/(2k + 1). 2
1, 2, 3, 5, 27, 565, 7085, 48771, 1266205, 9099507, 17602325, 128207979, 26494256091, 11147523830125, 84179432287299, 165269711096165, 281629680514649643, 4246732448623781667, 126774939137440139965, 1925041114036033717685, 14833445639443302757131 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(A103579(n)) is a subsequence.
Numbers n such that 2n + 1 divides 2^n + 1: 0, 1, 2, 5, 6, 9, 14, 18, 21, 26, 29, 30, 33, 41, 50, 53, ...
LINKS
EXAMPLE
1 is in this sequence because (2^1 + 1)/(2*1 + 1) = 1,
2 is in this sequence because (2^0 + 1)/(2*0 + 1) = 2,
3 is in this sequence because (2^5 + 1)/(2*5 + 1) = 3.
PROG
(PARI) s=[]; for(k=0, 100, t=(2^k + 1)/(2*k + 1); if(type(t)=="t_INT", s=concat(s, t))); s=vecsort(s, , 8) \\ Colin Barker, Nov 18 2014
CROSSREFS
Sequence in context: A064026 A121264 A141566 * A078736 A042669 A178376
KEYWORD
nonn
AUTHOR
EXTENSIONS
a(19) corrected by Colin Barker, Nov 18 2014
STATUS
approved

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Last modified March 19 07:41 EDT 2024. Contains 370958 sequences. (Running on oeis4.)