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A342923 Numbers k such that A342925(k) = k + 3*A003415(k). 11
120, 672, 963, 1036, 264768, 523776, 459818240, 1476304896 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
2^33 < a(9) <= A005820(6) = 51001180160.
LINKS
Table of n, a(n) for n=1..8.
MATHEMATICA
Select[Range[6*10^5], #3 == #1 + 3 #2 & @@ Prepend[Map[If[# < 2, 0, # Total[#2/#1 & @@@ FactorInteger[#]]] &, {#, DivisorSigma[1, #]}], #] &] (* Michael De Vlieger, Feb 25 2022 *)
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A342925(n) = A003415(sigma(n));
isA342923(n) = (A342925(n)==(n+(3*A003415(n))));
CROSSREFS
Cf. A003415, A342922, A342925.
Cf. A005820 (subsequence).
Sequence in context: A235768 A179963 A229568 * A292365 A306373 A356548
Adjacent sequences: A342920 A342921 A342922 * A342924 A342925 A342926
KEYWORD
nonn,more
AUTHOR
Antti Karttunen, Apr 08 2021
EXTENSIONS
a(8) from Antti Karttunen, Feb 25 2022
STATUS
approved

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Last modified August 29 23:09 EDT 2024. Contains 375519 sequences. (Running on oeis4.)