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Search: id:A134245
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| 2, 8, 88, 384, 1056, 2310, 207936, 417219, 2978610, 6215400, 9216124, 205006774, 255230655, 576178034, 1157525280, 2038109955, 3053762208, 10584038058, 25042362120, 1025402527504, 2304427934330, 11623068703428
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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The sequence of primes is sliced into subsequences of increasing lengths j=1,2,3,4,...: as (2) (3,5) (7,11,13) (17,19,23,29) (31,37,41,43,47) (...) where the sums of the subsequences are listed in A007468(j). If the sum A007468(j) is a multiple of j, we add A007468(j) to the list. This is a subsequence of A007468. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 16 2007
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FORMULA
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The set {A007468(j): j|A007468(j)}. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 16 2007
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EXAMPLE
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3+5=8 is a multiple of i=2 and is added to the sequence. 7+11+13 is not a multiple of 3 and is skipped. 17+19+23+29=88 is a multiple of 4 and is added to the sequence. 31+37+41+43+47=199 is not a multiple of 5 and is skipped.
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MAPLE
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A000217 := proc(n) n*(n+1)/2 ; end: A007468 := proc(n) add( ithprime(j), j=A000217(n-1)+1..A000217(n)) ; end: for n from 1 to 800 do a := A007468(n) ; if a mod n =0 then printf("%d, ", a) ; fi ; od: - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 16 2007
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CROSSREFS
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Cf. A134244, A134246.
Cf.: A007468.
Sequence in context: A052456 A000532 A083831 this_sequence A141313 A009144 A132316
Adjacent sequences: A134242 A134243 A134244 this_sequence A134246 A134247 A134248
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KEYWORD
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easy,nonn
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AUTHOR
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Enoch Haga (Enokh(AT)comcast.net), Oct 15 2007, Oct 16 2007
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EXTENSIONS
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Edited and corrected by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 16 2007
Corrected by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 16 2007
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