Characteristic function of primes: 1 if n is prime else 0.
0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0
1 seqfan posts
Thu Apr 5 07:20:02 CEST 2012 [seqfan] Definition issues with A121240 and A119523