23001

Appears in sequences

• Fermat pseudoprimes to base 2, also called Sarrus numbers or Poulet numbers.at n=36A001567
• Cubes written in base 7.at n=17A004637
• a(n) = (n^3 + 2*n)/3.at n=41A006527
• Denominators of continued fraction convergents to sqrt(89).at n=8A041159
• Denominators of continued fraction convergents to sqrt(356).at n=12A041675
• a(n) = (2*n+1)*(4*n^2+4*n+3)/3.at n=20A057813
• Denominator of coefficient G_n defined by Sum_{ (m,m') != (0,0)} 1/(m+m'*sqrt(-2))^(2*n) = (4*w)^(2*n)*G_n/(2*n)!, where 2w is one of the periods of the associated Weierstrass P-function.at n=39A069239
• Sum of squares of digits of n is equal to the largest prime factor of n reversed, where the largest prime factor is not a palindrome.at n=34A074303
• Sarrus numbers with more than 2 distinct prime factors.at n=19A080747
• Records in A007535.at n=35A098654
• The square root of A100252; the index of the least square number greater than 1 that is also an n-gonal number, or 0 if none exists.at n=42A100251
• Pseudoprimes (base-2) equal to product of 4 primes not necessarily distinct.at n=2A112441
• Sarrus numbers that become prime when two is added.at n=5A137198
• Values of y in solutions (x,y,z) to the Diophantine equation x^3-x^2+y^3-y^2=z^3-z^2, with 1<x<y<z arranged in order of increasing x.at n=24A138668
• Sarrus numbers A001567 that are not Carmichael numbers A002997.at n=27A153508
• Numerator of Euler(n, 3/20).at n=4A156751
• G.f.: A(q) = exp( Sum_{n>=1} A002129(n) * 3*A038500(n) * q^n/n ).at n=21A161804
• A trisection of A161804: a(n) = A161804(3n) for n>=0.at n=7A161805
• One third of product plus sum of three consecutive nonnegative integers; a(n)=(n+1)(n^2+2n+3)/3.at n=40A167875
• Increasing gaps between 2-pseudoprimes (upper end).at n=8A175737