21583

Appears in sequences

• Number of partitions of n into parts not of the form 23k, 23k+7 or 23k-7. Also number of partitions with at most 6 parts of size 1 and differences between parts at distance 10 are greater than 1.at n=38A035995
• a(n) = Sum_{k=1..n} T(n,k), array T as in A049790.at n=39A049791
• Start of record gap in odd semiprimes A046315.at n=10A114057
• G.f.: Sum_{n>=0} x^n * Product_{k=1..n} (1 - x^(n+k))/(1 - x^k).at n=40A260894
• Numbers k such that (38*10^k - 119) / 9 is prime.at n=22A278695
• Numbers such that the sum of the reverse of their aliquot parts is equal to the reverse of the sum of their aliquot parts.at n=16A278948
• a(n) is the lower end of a record gap A349995(n) between consecutive odd squarefree semiprimes (A046388).at n=9A350098
• Numbers k such that the decimal expansion of the sum of the reciprocals of the digits of k starts with the digits of k in the same order.at n=7A354466
• a(n) is the number of shallow permutations of length n that avoid 123.at n=13A382574