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A112814 Numbers k such that lcm(1,2,3,...,k)/5 equals the denominator of the k-th harmonic number H(k). 12
105, 106, 107, 108, 109, 2625, 2626, 2627, 2628, 2629, 2630, 2631, 2632, 2633, 2634, 2635, 2636, 2637, 2638, 2639, 2640, 2641, 2642, 2643, 2644, 2645, 2646, 2647, 2648, 2649, 2650, 2651, 2652, 2653, 2654, 2655, 2656, 2657, 2658, 2659, 2660, 2661, 2662 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
When 5 occurs in A110566.
LINKS
MATHEMATICA
f[n_] := LCM @@ Range[n]/Denominator[ HarmonicNumber[n]]; Select[ Range[2662], f[ # ] == 5 &]
PROG
(PARI) isok(n) = lcm(vector(n, i, i)) == 5*denominator(sum(i=1, n, 1/i)); \\ Michel Marcus, Mar 07 2018
CROSSREFS
Sequence in context: A231578 A104437 A361417 * A058179 A260461 A090055
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Sep 17 2005
STATUS
approved

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Last modified March 29 07:27 EDT 2024. Contains 371265 sequences. (Running on oeis4.)