19542

Appears in sequences

• Boustrophedon transform of 1 & primes: 1,2,3,5,7,...at n=8A000732
• Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite SGT = Sigma-2 [Si64O128].4R starting with a T4 atom.at n=13A019238
• "EFK" (unordered, size, unlabeled) transform of 2,4,6,8,...at n=15A032309
• Denominators of convergents to Pi by Farey fractions.at n=40A063673
• Average of twin-prime pairs for pairs that are expressible as the sum of two triangular numbers.at n=36A117313
• Expansion of (chi(-x) * chi(-x^19))^(-2) in powers of x where chi() is a Ramanujan theta function.at n=31A134004
• Numbers that are divisible by exactly 3 primes (counted with multiplicity) and sandwiched between primes.at n=40A171179
• Numbers k such that k is the average of four consecutive primes k-11, k-1, k+1 and k+11.at n=19A259025
• Length of n-th iterate of the mapping 00->0010, 01->100, 10->001 in A289165.at n=17A289168
• Number of prefix normal palindromes of length n.at n=34A308465