%I #16 Mar 14 2020 05:58:04
%S 22,26,33,34,38,39,44,46,51,52,55,57,58,62,65,66,68,69,74,76,77,78,82,
%T 85,86,87,93,94,95,99,102,104,106,110,111,114,116,117,118,119,121,122,
%U 123,124,129,130,132,133,134,136,138,141,142,143,145,146,148,152,153
%N Composite numbers k such that Ramanujan's function tau(k) (A000594) is not divisible by k.
%H Amiram Eldar, <a href="/A063940/b063940.txt">Table of n, a(n) for n = 1..10000</a>
%e 22 is a term because Ramanujan's tau(22) = 18643272 and 18643272 mod 22 = 10.
%t Select[ Range[ 70 ], Mod[ CoefficientList[ Take[ Expand[ Product[ (1 - x^k)^24, {k, 1, 70} ] ], 70 ], x ][ [ # ] ], # ] != 0 && ! PrimeQ[ # ] & ]
%t (* First do *) <<NumberTheory`Ramanujan` (* then *) Select[ Range[ 153], Mod[ RamanujanTau[ # ], # ] != 0 && ! PrimeQ[ # ] &] (* _Dean Hickerson_, Jan 03 2003 *)
%Y Cf. A000594, A063938, A007659.
%K nonn
%O 1,1
%A _Robert G. Wilson v_, Aug 31 2001
|