24493

Appears in sequences

• Smaller terms in the pairs of numbers (a < b) in the sequence {a,b}-> {Max[{a,b}]-Min[{a,b}],k*Min[{a,b}]} with k=3 and the first pair {a=1,b=2}. See A075256.at n=47A075257
• a(n) = 16*n^2 + 4*n + 1.at n=39A082041
• a(1) = 1, a(2) = 3, a(n) = LCM of all the previous terms + 1.at n=5A082732
• Least positive k such that 2^n + k is a Chen prime and 2^n + k + 2 is a brilliant number.at n=19A109364
• p^2-p+1 central polygonal numbers with prime indices A002061(prime(n)).at n=36A119959
• Numbers k such that 6*prime(k) -+ {1,5} are all prime.at n=34A174393
• Irregular table read by rows: T(0,0) = 2 and T(n,2k) = T(n-1,k)+1, T(n,2k+1) = T(n-1,k)*(T(n-1,k)+1) for 0 <= k < 2^(n-1).at n=45A273317
• Alternate version of A273317 with rows sorted in ascending order.at n=53A273338
• a(n) = Sum_{p in P} (H(2,p)^2)/2, where P is the set of partitions of n, and H(2,p) is the number of hooks of length 2 in p.at n=28A302348
• Number of compositions (ordered partitions) of n into hexagonal numbers (A000384).at n=42A322798
• Positive integers k such that the decimal representation of 2^k ends with some permutation of the string "0123456789".at n=5A347164
• Numbers k such that k, k+1, k+2, k+3 have 2, 3, 4, 5 prime factors respectively, counted with multiplicity.at n=30A363391
• Intersection of A002061 and A016105.at n=34A370519
• Lexicographically earliest sequence of positive integers a(1), a(2), a(3), ... such that for any n > 0, S(n) = Sum_{k = 1..n} b(k)/a(k) < 1, where {b(k)} is the sequence {7/6, 5/4, 5/4, 5/4, ...}.at n=4A376062
• Squarefree semiprimes k such that k+1 is the product of three distinct primes and k+2 is the product of four distinct primes.at n=37A376352