25391

Properties

Appears in sequences

• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (Fibonacci numbers), t = (composite numbers).at n=26A024461
• Expansion of 1/((1-2x)(1-3x)(1-5x)(1-9x)).at n=4A025933
• Primes that are palindromic in base 5.at n=33A029973
• a(n) = prime(100*n).at n=27A031921
• Balanced primes separated from the next lower and next higher prime neighbors by 18.at n=2A053073
• Primes p whose reciprocal has period (p-1)/10.at n=33A056215
• a(n) = 48*n^2 - 1.at n=23A065532
• Balanced primes of order four.at n=30A082079
• Primes of the form 3*m^2 - 1.at n=26A089682
• a(n) is the smallest prime divisor of the number obtained from concatenation of the first n primes.at n=12A104644
• Primes p for which Sum_{1 <= n < p} (n!|p) == 0 (mod p), where (n!|p) is the Legendre symbol.at n=38A131652
• Father primes of order 11.at n=25A136080
• Primes of the form 12*n^2-1.at n=25A143830
• Primes p such that the multiplicative order of 2 modulo p is (p-1)/10.at n=34A152310
• Larger of 3 consecutive prime numbers such that p1*p2*p3*d1*d2=average of twin prime pairs; p1,p2,p3 consecutive prime numbers; d1(delta)=p2-p1, d2(delta)=p3-p2.at n=20A153411
• Primes p dividing every A167859(m) from m=(p-1)/2 to m=(p-1).at n=31A167860
• Consider all distinct functions f representable as x -> x^x^...^x with n x's and parentheses inserted in all possible ways; sequence gives difference between numbers of f with f(0)=1 and numbers of f with f(0)=0, with conventions that 0^0=1^0=1^1=1, 0^1=0.at n=15A211192
• Primes which have the same (base 10) digital sum A007953 as the next smaller and next larger prime.at n=1A217875
• Equals two maps: number of nX3 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..1 nX3 array.at n=5A220403
• T(n,k)=Equals two maps: number of nXk binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal, diagonal and antidiagonal neighbors in a random 0..1 nXk array.at n=33A220406