login
A167311
Totally multiplicative sequence with a(p) = 10*(p+2) for prime p.
1
1, 40, 50, 1600, 70, 2000, 90, 64000, 2500, 2800, 130, 80000, 150, 3600, 3500, 2560000, 190, 100000, 210, 112000, 4500, 5200, 250, 3200000, 4900, 6000, 125000, 144000, 310, 140000, 330, 102400000, 6500, 7600, 6300, 4000000, 390, 8400, 7500
OFFSET
1,2
LINKS
FORMULA
Multiplicative with a(p^e) = (10*(p+2))^e. If n = Product p(k)^e(k) then a(n) = Product (10*(p(k)+2))^e(k).
a(n) = A165831(n) * A166590(n) = 10^bigomega(n) * A166590(n) = 10^A001222(n) * A166590(n).
MATHEMATICA
a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((fi[[All, 1]] + 2)^fi[[All, 2]])); Table[a[n]*10^PrimeOmega[n], {n, 1, 100}] (* G. C. Greubel, Jun 07 2016 *)
f[p_, e_] := (10*(p+2))^e; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Oct 18 2023 *)
CROSSREFS
KEYWORD
nonn,easy,mult
AUTHOR
Jaroslav Krizek, Nov 01 2009
STATUS
approved