29401

Properties

Appears in sequences

• a(0)=1, a(1)=1, a(2)=1, a(n) = 2*a(n-1) + a(n-2) + 1.at n=13A033539
• Numerator of probability that 2 elements of S_n chosen at random (with replacement) generate S_n.at n=9A040173
• a(n) = 6*a(n-1) - a(n-2) + 2, with a(0)=1, a(1)=4.at n=6A072221
• Primes p such that the period of the decimal expansion of 1/p is a square.at n=33A072858
• Primes of the form n^2*totient(n)+1 (or A053191(n) + 1).at n=12A076669
• Upper twin primes of upper twin prime index.at n=23A088463
• Primes of the form 6*k^2 + 1.at n=19A090687
• Expansion of (5-x^2)/((1+x)*(1-6*x+x^2)).at n=5A098212
• Sieve performed by successive iterations of steps where step m is: keep m terms, remove the next 3 and repeat; as m = 1,2,3,.. the remaining terms form this sequence.at n=21A112561
• Primes p for which the period length of 1/p is a perfect power, A001597.at n=43A128948
• a(n) = 24*n^2 + 1.at n=35A158547
• Primes of the form 3*m^2 - 2.at n=17A201715
• Primes p of the form 420k + 1 for some k.at n=27A217587
• Primes p of the form p = 1 + 840*k for some k.at n=16A217862
• Numbers k such that the distance between the k-th triangular number and the nearest square is at most 1.at n=22A229083
• Numbers k such that the distance between the k-th triangular number and the nearest square is exactly 1.at n=17A229131
• Primes p such that a Heronian triangle with a fixed side length of 3 contains p as another side length.at n=2A230666
• Number of tilings of an n X 1 rectangle by tiles of dimension 1 X 1 and 2 X 1 such that every tile is next to a tile of different size.at n=35A245596
• Centered 25-gonal primes.at n=11A276264
• Length of shortest prefix of the characteristic sequence of the primes A010051 that contains all possible length-n blocks appearing in that sequence.at n=21A280418