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A255680
a(n) = n*(n mod 3)*(n mod 5).
1
0, 1, 8, 0, 16, 0, 0, 14, 48, 0, 0, 22, 0, 39, 112, 0, 16, 68, 0, 76, 0, 0, 44, 138, 0, 0, 52, 0, 84, 232, 0, 31, 128, 0, 136, 0, 0, 74, 228, 0, 0, 82, 0, 129, 352, 0, 46, 188, 0, 196, 0, 0, 104, 318, 0, 0, 112, 0, 174, 472, 0, 61, 248, 0, 256, 0, 0, 134, 408, 0, 0, 142, 0, 219, 592, 0, 76, 308, 0, 316, 0, 0, 164, 498, 0, 0, 172, 0
OFFSET
0,3
COMMENTS
a(n) = 0 for n = 3k and 5k, k=0,1,2,...
LINKS
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0,0, 0, 0, 0, 0, 0, -1).
FORMULA
Empirical g.f.: x*(8*x^28 + 6*x^27 + 8*x^25 + 42*x^22 + 16*x^21 + 44*x^18 + 52*x^16 + 14*x^15 + 112*x^13 + 39*x^12 + 22*x^10 + 48*x^7 + 14*x^6 + 16*x^3 + 8*x + 1) / ((x - 1)^2*(x^2 + x + 1)^2*(x^4 + x^3 + x^2 + x + 1)^2*(x^8 - x^7 + x^5 - x^4 + x^3 - x + 1)^2). - Colin Barker, Mar 02 2015
a(n) = n*A010872(n)*A010874(n). - Michel Marcus, Mar 03 2015
MATHEMATICA
Table[x*Mod[x, 3]*Mod[x, 5], {x, 0, 100}]
LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1}, {0, 1, 8, 0, 16, 0, 0, 14, 48, 0, 0, 22, 0, 39, 112, 0, 16, 68, 0, 76, 0, 0, 44, 138, 0, 0, 52, 0, 84, 232}, 100] (* Harvey P. Dale, Sep 06 2015 *)
PROG
(PARI) vector(101, n, (n-1)*((n-1)%3)*((n-1)%5))
(Magma) [n*(n mod 3)*(n mod 5): n in [0..80]]; // Vincenzo Librandi, Mar 03 2015
CROSSREFS
Cf. A255642.
Sequence in context: A297811 A359686 A325318 * A265115 A214205 A278147
KEYWORD
nonn,easy
AUTHOR
Zak Seidov, Mar 01 2015
EXTENSIONS
Typo in first Mathematica program corrected by Harvey P. Dale, Jul 03 2021
STATUS
approved