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A128649 Numbers m such that A128646(m) = A128648(m). 3
1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 16, 17, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 65, 66, 71, 72, 73, 74, 75, 76, 77, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 539, 540, 541, 542, 543, 600, 601, 602, 603, 604, 605, 606, 607, 608, 609, 610 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Terms of this sequence are 1..5, 7..11, 14..17, 21..35, 65..66, 71..77, 81..93, 539..543, 600..639, 644..650, 707..818, 1152..1185, 4502..4577, 4601..4823, 4893..5003, 7483..7633, ...
LINKS
Eric Weisstein's World of Mathematics, Prime Sums
MATHEMATICA
f=0; g=0; Do[p=Prime[n]; f=f+1/(p-1); g=g+(-1)^(n+1)*1/(p-1); kf=Denominator[f]; kg=Denominator[g]; If[Equal[kf, kg], Print[n]], {n, 1, 10000}]
CROSSREFS
Cf. A128648 (denominator(Sum_{k=1..n} (-1)^(k+1)/(prime(k)-1))).
Cf. A128646 (denominator(Sum_{k=1..n} 1/(prime(k)-1))).
Sequence in context: A359905 A316465 A004764 * A032894 A032853 A023748
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Mar 18 2007
STATUS
approved

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Last modified February 22 02:45 EST 2024. Contains 370239 sequences. (Running on oeis4.)