178709

Appears in sequences

• a(n+6) = -a(n+5) + a(n+4) + 3a(n+3) + a(n+2) - a(n+1) - a(n). a(n) = sign(n) if abs(n)<=3.at n=43A001945
• Strong pseudoprimes to base 7.at n=27A020233
• Strong pseudoprimes to base 37.at n=33A020263
• Strong pseudoprimes to base 50.at n=35A020276
• Strong pseudoprimes to base 61.at n=31A020287
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 33.at n=21A031621