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A133482
a(p_1^e_1*p_2^e_2*.....*p_m^e_m) = (p_1^p_1)^e_1*(p_2^p^2)^e_2*.....*(p_m^p_m)^e_m where p_1^e_1*p_2^e_2*.....*p_m^e_m is the prime decomposition of n.
2
1, 4, 27, 16, 3125, 108, 823543, 64, 729, 12500, 285311670611, 432, 302875106592253, 3294172, 84375, 256, 827240261886336764177, 2916, 1978419655660313589123979, 50000, 22235661, 1141246682444, 20880467999847912034355032910567, 1728, 9765625, 1211500426369012, 19683, 13176688, 2567686153161211134561828214731016126483469, 337500
OFFSET
1,2
COMMENTS
Totally multiplicative sequence with a(p) = p^p for prime p. - Jaroslav Krizek, Oct 17 2009
Sum_{n>=1} 1/a(n) = Product_{p prime} (1 + 1/(p^p - 1)) = 1.3850602852044891763... - Amiram Eldar, Dec 08 2020
LINKS
FORMULA
Multiplicative with a(p^e) = p^(pe). If n = Product p(k)^e(k) then a(n) = Product p(k)^(p(k)*e(k)). - Jaroslav Krizek, Oct 17 2009
EXAMPLE
a(6) = a(2^1*3^1) = 2^2^1*3^3^1 = 4*27 = 108.
MAPLE
A133482 := proc(n) local ifs, f ; if n = 1 then 1; else ifs := ifactors(n)[2] ; mul( (op(1, f)^op(1, f))^op(2, f), f=ifs) ; fi ; end: seq(A133482(n), n=1..30) ; # R. J. Mathar, Nov 30 2007
MATHEMATICA
f[p_, e_] := (p^(p*e)); a[1] = 1; a[n_] := Times @@ (f @@@ FactorInteger[n]); Array[a, 30] (* Amiram Eldar, Dec 08 2020 *)
CROSSREFS
Sequence in context: A218362 A108138 A119361 * A108139 A351365 A200768
KEYWORD
nonn,mult
AUTHOR
Masahiko Shin, Nov 29 2007
EXTENSIONS
Corrected and extended by R. J. Mathar, Nov 30 2007
STATUS
approved