34649

Properties

Appears in sequences

• a(n) = E(n+1) - 2*E(n), where E(i) is the Euler number A000111(i).at n=9A000708
• Triangle T(n,k) = P(n,k)/2, n >= 2, 1 <= k < n, of one-half of number of permutations of 1..n such that the differences have k runs with the same signs.at n=34A008970
• Even-indexed Chebyshev U-polynomials evaluated at sqrt(10)/2.at n=5A057080
• Smaller of twin primes whose middle term is a multiple of A002110(4)=210.at n=30A060230
• Smaller of twin primes whose middle term is a multiple of A002110(5)=2310.at n=4A060231
• Primes p such that 11 is the largest of all prime factors of the numbers between p and the next prime (cf. A052248).at n=25A080187
• Highly cototient numbers that are prime, or intersection of A000040 and A100827.at n=42A105440
• Denominators in continued fraction expansion of sqrt(3/5).at n=10A145543
• Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 10001-11111 pattern in any orientation.at n=11A147090
• Union of A057080 and A001090.at n=10A177187
• List of 4-tuples of twin primes q, p, p+2 and q+2 such that 3*q<p<(p+2)<3*(q+2).at n=33A177335
• Half the number of nX3 binary arrays with no element equal to a strict majority of its knight-move neighbors.at n=8A183394
• T(n,k)=Half the number of nXk binary arrays with no element equal to a strict majority of its knight-move neighbors.at n=57A183397
• Primes of the form 6n^2 - 7.at n=28A201792
• Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2<x^2+y^2.at n=36A211635
• The triangle associated with the family of polynomials W_n(x).at n=49A228356
• Number of permutations of [n] having a shortest ascending run of length 4.at n=8A228671
• Lesser twin prime p such that p^2-p-2 is the average of a larger twin prime pair.at n=35A231652
• Primes of form n^2 + 10000.at n=29A256838
• Primes that can be generated by the concatenation in base 3, in ascending order, of two consecutive integers read in base 10.at n=42A287300