28669

Properties

Appears in sequences

• Primes p = p_(n+1) such that p_n + p_(n+2) = 2*p_(n+1) + 12.at n=31A095673
• Integers k such that the k-th triangular number t_k has all its base-12 digits contained in {1,5,7,11}.at n=10A118711
• Primes of the form 7*2^k-3 or 7*2^k+3.at n=9A127703
• The number of edges on a piece of paper that has been folded n times (see comments for more precise definition).at n=24A133257
• Irregular table with first row containing the single term 3; in the n-th row, n>=2, we list in increasing order those d=2^(n+1)-a, for each term a in all the preceding rows, such that d is prime.at n=37A152871
• a(n) = 7*2^n - 3.at n=12A156127
• a(n) = a(n-1) + a(n-2) + n^2 for n >= 3, a(1)=2, and a(2)=5.at n=15A179992
• Primes of the form 7n^3-3.at n=3A200917
• Primes of the form 7n^2 - 3.at n=7A201849
• Expansion of (1+4*x+5*x^2-x^3)/((1-x)*(1+x)*(1-2*x^2)).at n=25A220753
• Primes in the chain of repeated application of x->2*x+3, starting at x=11.at n=5A225582
• Number of numbers in row n of the array at A243851.at n=23A243853
• Primes p such that sigma(sigma(2p-1)) is a prime.at n=1A247790
• Numbers k such that sigma(sigma(2k-1)) is a prime p.at n=3A247821
• Intersection of A013917 and A071150.at n=19A255017
• a(n) = prime(n)^prime(n) mod n^n.at n=5A262208
• Values of n such that prime(n) does not divide any 10-digit pandigital number (i.e. any value in A050278).at n=8A292703
• Primes p such that A001175(p) = (p-1)/6.at n=34A308791
• Discriminants of totally real cubic fields in which every norm-positive unit is totally positive.at n=3A329769
• a(n) = 1 + Sum_{k=1..n-4} a(k) * a(n-k-4).at n=28A346076