21107

Properties

Appears in sequences

• Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite FER = Ferrierite Na2Mg2[Al6Si30O72].18H2O starting with a T2 atom.at n=13A019133
• Numerators of continued fraction convergents to sqrt(44).at n=12A041074
• Numerators of continued fraction convergents to sqrt(176).at n=6A041324
• Discriminants of imaginary quadratic fields with class number 25 (negated).at n=35A056987
• Primes produced by repeated application of the formula p -> (6p +- 5) starting at the prime 2.at n=23A086321
• a(n) = smallest prime > a(n-1) such that a(n)+a(n-1) is multiple of k, a(1)=2, k=101.at n=31A178468
• Primes that are the average of the members of emirp pairs.at n=9A178581
• Nonpalindromic primes that are the average of the members of emirp pairs.at n=1A178585
• Primes congruent to 1 mod 61.at n=38A212378
• Number of rows with the value true in the truth tables of all bracketed formulas with n distinct propositions p_1, ..., p_n connected by the binary connective of m-implication (case 3).at n=8A218185
• Primes of the form 15*k^2 - 15*k + 17.at n=27A220081
• Number of set partitions of [n] such that j is member of block b only if b = 1 or at least one of j-1, ..., j-5 is member of a block >= b-1.at n=9A287668
• Prime time primes (of the form HMMSS with primes H < 24 and MM, SS < 60) such that the corresponding number of seconds after midnight is also prime.at n=7A295000
• Numbers of the form HMMSS with primes H < 24 and MM, SS < 60, for which the number of seconds after midnight, 3600*H+60*MM+SS, is also prime.at n=20A295011
• Prime time primes on 6-digit clocks, second definition: primes of the form HMMSS where H, MM, SS are primes, H < 24, MM and SS < 60.at n=23A295013
• Number of integer partitions of n whose maximal anti-runs have distinct maxima.at n=50A375133
• a(n) is the least prime p such that p + 7*k*(k+1) is prime for 0 <= k <= n-1 but not for k=n.at n=9A376675
• Number of fundamentally distinct graceful labelings in a maximally graceful tree with n vertices.at n=12A379102
• Prime numbersat n=2373