A365470 (2,6)-imperfect numbers.
6, 12, 24, 30, 60, 120, 252, 384, 510, 864, 1020, 1260, 1920, 2040, 2640, 5418, 12960, 21420, 21672, 32640, 75852, 98304, 108864, 131070, 262140, 346752, 379260, 491520, 524280, 1982988, 2296728, 5504940, 6447420, 8355840, 8388480, 36747648, 39009600, 57024000
Offset: 1
Keywords
Links
- Amiram Eldar, Table of n, a(n) for n = 1..56
- László Tóth, A survey of the alternating sum-of-divisors function, arXiv:1111.4842 [math.NT], 2011-2014. See p. 7.
Crossrefs
Programs
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Mathematica
beta[n_]:=Sum[d*LiouvilleLambda[n/d],{d,Divisors[n]}]; Select[Range[5500],#==6*beta[beta[#]]&] (* Ivan N. Ianakiev, Sep 12 2023 *) -
PARI
beta(n) = sumdiv(n, d, d*(-1)^bigomega(n/d)); isok(k) = 6*beta(beta(k)) == k;
Comments