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A167354 Totally multiplicative sequence with a(p) = (p-2)^2 = p^2-4p+4 for prime p. 1
1, 0, 1, 0, 9, 0, 25, 0, 1, 0, 81, 0, 121, 0, 9, 0, 225, 0, 289, 0, 25, 0, 441, 0, 81, 0, 1, 0, 729, 0, 841, 0, 81, 0, 225, 0, 1225, 0, 121, 0, 1521, 0, 1681, 0, 9, 0, 2025, 0, 625, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

FORMULA

Multiplicative with a(p^e) = ((p-2)^2)^e. If n = Product p(k)^e(k) then a(n) = Product ((p(k)-2)^2)^e(k). a(2k) = 0 for k >= 1, a(n) = A166586(n)^2.

MATHEMATICA

a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((fi[[All, 1]] - 2)^fi[[All, 2]])); Table[a[n]^2, {n, 1, 100}] (* G. C. Greubel, Jun 11 2016 *)

CROSSREFS

Cf. A166586.

Sequence in context: A007394 A067153 A057405 * A005066 A076262 A167301

Adjacent sequences:  A167351 A167352 A167353 * A167355 A167356 A167357

KEYWORD

nonn,mult

AUTHOR

Jaroslav Krizek, Nov 01 2009

STATUS

approved

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Last modified April 19 11:58 EDT 2021. Contains 343114 sequences. (Running on oeis4.)