23521

Appears in sequences

• Pseudoprimes to base 3.at n=34A005935
• Base-6 Armstrong or narcissistic numbers, written in base 6.at n=11A010347
• Numerator of sum of -7th powers of divisors of n.at n=5A017677
• Pseudoprimes to base 39.at n=37A020167
• Strong pseudoprimes to base 3.at n=11A020229
• Strong pseudoprimes to base 9.at n=24A020235
• Strong pseudoprimes to base 13.at n=12A020239
• Strong pseudoprimes to base 14.at n=11A020240
• Strong pseudoprimes to base 27.at n=24A020253
• Strong pseudoprimes to base 39.at n=15A020265
• Strong pseudoprimes to base 40.at n=20A020266
• Strong pseudoprimes to base 42.at n=16A020268
• Strong pseudoprimes to base 81.at n=34A020307
• Base-3 Euler-Jacobi pseudoprimes.at n=16A048950
• Odd numbers n for which 17 is the smallest i (>= 1) with Jacobi symbol J(i,n) getting either a value 0 or -1.at n=30A112077
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (-1, 1, 1), (1, -1, -1), (1, 1, 0)}.at n=9A149111
• Terms of A122780 which are not Carmichael numbers A002997.at n=33A153514
• a(n) = 30*n^2 + 1.at n=28A158558
• 28-gonal numbers: a(n) = n*(13*n - 12).at n=43A161935
• Euler pseudoprimes to base 3: composite integers such that abs(3^((n - 1)/2)) == 1 mod n.at n=19A262051