80910

Appears in sequences

• Values of k such that k - 1 and k + 1 are twin primes and 3*k^9 - 1 and 3*k^9 + 1 are also twin primes.at n=5A108134
• Records in A109734.at n=24A109739
• Averages of twin primes such that the sum of the lower, average and upper parts of the twin primes are averages of other twin primes.at n=27A132929
• Composite numbers such that the square root of the sum of squares of their prime factors is a prime.at n=28A134607
• Sequence of the "Natural Jewels": a natural jewel is a number that is totally enclosed by prime numbers in a version of Ulam Spiral.at n=29A172294
• Sum of all even numbers in Collatz (3x+1) trajectory of n.at n=30A213909
• Numbers on the square spiral board that are enclosed by four primes.at n=29A341542
• Those primitive elements of A337386 that have exactly one primitive nondeficient divisor (A006039).at n=32A341604