25877

Appears in sequences

• MacMahon's solid partitions of n in which 3 is the smallest summand.at n=13A002044
• Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 13.at n=29A051978
• Composite numbers not divisible by 2 or 3 which in base 3 contain their largest proper factor as a substring.at n=23A063132
• Composite numbers k that divide Fibonacci(k+1).at n=12A069107
• Odd Fibonacci pseudoprimes: odd composite numbers k such that either (1) k divides Fibonacci(k-1) if k == +-1 (mod 5) or (2) k divides Fibonacci(k+1) if k == +-2 (mod 5).at n=19A081264
• Numbers k that divide Fibonacci(k+1) but do not divide Fibonacci(k) + 1.at n=10A094412
• Semiprimes k that divide Fibonacci(k+1).at n=9A177745
• Composite numbers k that divide both Fibonacci(k+1) and Fibonacci(2k+1)-1.at n=11A182504
• Composite numbers k that divide Fibonacci(k+1) or Fibonacci(k-1).at n=24A182554
• Lucas pseudoprimes.at n=23A217120
• Numbers of the form p*q, p and q prime with q=2*p+3.at n=14A226754
• a(n) = (A269590(n)^2 + 4)/5^n, n >= 0.at n=12A269594
• Odd composite integers m such that F(m)^2 == 1 (mod m), where F(m) is the m-th Fibonacci number.at n=33A337231
• Odd composite integers m such that A000032(2*m-J(m,5)) == J(m,5) (mod m), where J(m,5) is the Jacobi symbol.at n=23A339517
• Odd composite integers m such that A001906(m-J(m,5)) == 0 (mod m) and gcd(m,5)=1, where J(m,5) is the Jacobi symbol.at n=40A340097
• Odd composite integers m such that A000045(2*m-J(m,5)) == 1 (mod m), where J(m,5) is the Jacobi symbol.at n=23A340118
• Numbers m such that abs(K(m+1) - K(m)) = 2, and both m and m+1 are squarefree (A005117), where K(m) = A002034(m) is the Kempner function.at n=12A346212
• a(n) is the first start of a sequence of exactly n members of A175648 under the map k -> 3*k+4.at n=5A352137