24371

Properties

Appears in sequences

• Double and reverse digits.at n=9A036447
• Reverse or double: if reverse of a(n) > a(n), then a(n+1) = a(n) reversed, otherwise a(n+1) = 2*a(n).at n=13A041013
• Numerators of continued fraction convergents to sqrt(273).at n=7A041512
• Prime number spiral (clockwise, Southeast spoke).at n=26A054564
• Primes in which the unit place digit is 1 and the k-th most significant digit is prime (2,3,5,7) if k is prime else is composite (4,6,8,9,0).at n=32A089704
• Primes from merging of 5 successive digits in decimal expansion of e.at n=27A104846
• a(1) = a(2) = a(3) = 1; for n>3, a(n) = a(n-1) + a(n-2) + a(n-3) iff n-1 is prime, otherwise a(n) = a(n-1) + 1.at n=33A113057
• Prime numbers q of primitive Pythagorean triangles such that perimeters are averages of twin prime pairs, p+1=q(prime), a=q^2-p^2, c=q^2+p^2, b=2*p*q, ar=a*b/2; s=a+b+c, s-+1 are primes.at n=36A155187
• Strong primes p: adding 2 to any one digit of p produces a prime number (no digits 8 & 9 in p).at n=14A158641
• Primes of the form 7n^2 + 4.at n=16A201605
• Numbers k such that (11^k - 2^k)/9 is prime.at n=8A210506
• Numbers n such that (7^n - 4^n)/3 is prime.at n=7A213073
• Primes p such that 10*p-1, 10*p-3, 10*p-7 and 10*p-9 are all prime.at n=14A243408
• Number of (n+1)X(3+1) arrays of permutations of 0..n*4+3 with each element having directed index change -2,0 -1,0 0,-1 or 1,1.at n=9A264623
• Prime time primes (of the form HMMSS with primes H < 24 and MM, SS < 60) such that the corresponding number of seconds after midnight is also prime.at n=34A295000
• Number of free deltoidal hexecontahedron polykites with n faces.at n=10A340635
• a(n) is the least m such that A341284(m) = 2*n*prime(m+1) - prime(m).at n=45A342027
• Number of partitions of the (n+2)-multiset {0,...,0,1,2} with n 0's into distinct multisets.at n=33A346822
• Lesser twin primes p such that 4*p is the sum of two consecutive primes.at n=23A350736
• Largest number reachable starting from 1 and taking n steps either doubling or doubling+reversing.at n=9A371966