73727

Properties

Appears in sequences

• Class 1+ primes: primes of the form 2^i*3^j - 1 with i, j >= 0.at n=31A005105
• Number of partitions satisfying 0 < cn(1,5) + cn(4,5).at n=44A039898
• Primes whose consecutive digits differ by 4 or 5.at n=32A048416
• Primes of the form 9*2^n-1.at n=3A050524
• Start with n, apply k->2k+1 until reach new record prime; sequence gives record primes.at n=8A051919
• Expansion of (1+x^2-x^3)/((1-x)*(1-2*x)).at n=15A052996
• Smallest prime with Hamming weight n (i.e., with exactly n 1's when written in binary).at n=13A061712
• a(1) = 2, a(n+1) = smallest squarefree number == 1 (mod a(n)) and > a(n).at n=16A076698
• Duplicate of A076698.at n=16A076993
• Smallest prime p with bigomega(p+1)=n, where bigomega(m)=A001222(m) is the number of prime divisors of m (counted with multiplicity).at n=14A118883
• Smallest prime of the form k*2^n - 1, for k >= 2.at n=13A127581
• a(n) = 72*n^2 - 1.at n=31A158738
• Primes of the form 2*p^2 + 4*p + 1, where p is also prime.at n=17A164041
• Increasing sequence S generated by these rules: a(1)=1, and if x is in S then both 3x+2 and 4x+3 are in S.at n=45A191145
• Primes neighboring a 3-smooth number.at n=58A219528
• Primes of the form m = 2^i + 2^j - 1, where i > j >= 0.at n=43A239712
• Integers of the form 8k+7 that can be written as a sum of four distinct squares of the form m, m+2, m+4, m+5, where m == 1 (mod 4).at n=33A243579
• Record values in A135141.at n=29A246347
• Primes p such that sigma(2p+1) = 3*(p+1).at n=4A246914
• Primes of the form 2^i * 3^j - 1 for positive i, j.at n=25A268640