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A134245
Terms in A007468 which are multiples of their indices.
5
2, 8, 88, 384, 1056, 2310, 207936, 417219, 2978610, 6215400, 9216124, 205006774, 255230655, 576178034, 1157525280, 2038109955, 3053762208, 10584038058, 25042362120, 1025402527504, 2304427934330, 11623068703428
OFFSET
1,1
COMMENTS
If A007468(j) is a multiple of j, we add A007468(j) to this sequence. This sequence is a subsequence of A007468. - R. J. Mathar, Nov 16 2007
LINKS
FORMULA
a(n) = A007468(A134244(n)).
EXAMPLE
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.
MAPLE
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, Nov 16 2007
CROSSREFS
KEYWORD
nonn
AUTHOR
Enoch Haga, Oct 15 2007, Oct 16 2007
EXTENSIONS
Edited and corrected by R. J. Mathar, Nov 16 2007
Corrected by R. J. Mathar, Nov 16 2007
Edited by Max Alekseyev, Nov 08 2011
STATUS
approved