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A079393
Numbers for which Ramanujan's tau function is negative.
2
2, 4, 6, 7, 9, 10, 12, 13, 17, 20, 21, 22, 25, 27, 30, 31, 32, 35, 37, 38, 39, 43, 44, 45, 46, 49, 51, 53, 56, 58, 59, 60, 65, 66, 67, 72, 75, 76, 77, 82, 83, 85, 89, 92, 93, 94, 96, 99, 103, 104, 105, 110, 111, 112, 113, 114, 116, 122, 125, 126, 127, 129
OFFSET
0,1
LINKS
EXAMPLE
A000594(2) = -24, so a(1) = 2.
MATHEMATICA
Select[Range[200], RamanujanTau[#] < 0 &] (* Carl Najafi, Sep 09 2011 *)
PROG
(PARI) T(n)=n*(n+1)/2 rtau3(n)=local(y, j); y=0; j=1; while (T(j-1)<n, j++); j--; for (i=1, j, y=y-(-1)^i*(2*i-1)*x^(T(i-1))); y=y^8; polcoeff(y, n-1) for (n=1, 100, if (rtau3(n)<0, print1(n", ")))
(PARI) isok(n) = ramanujantau(n) < 0; \\ Michel Marcus, Jan 20 2019
CROSSREFS
Sequence in context: A248612 A247000 A213356 * A047512 A026273 A184658
KEYWORD
nonn
AUTHOR
Jon Perry, Jan 06 2003
STATUS
approved