20533

Properties

Appears in sequences

• Number of partitions of n into parts not of the form 21k, 21k+2 or 21k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 9 are greater than 1.at n=43A035980
• Sums of 7 distinct powers of 3.at n=37A038469
• Least prime in A031928 (lesser of 10-twins) whose distance to the next 10-twin is 6*n.at n=27A052354
• Primes p such that x^59 = 2 has no solution mod p.at n=37A059312
• Irregular primes with irregularity index three.at n=31A060975
• Primes in A003154.at n=30A083577
• Numerator of Sum/Product of first n Lucas numbers A000032[n].at n=26A121709
• Primes p such that q = 4p^2 + 1 and r = 4q^2 + 1 are also prime.at n=29A122424
• Primes congruent to 22 mod 53.at n=39A142552
• Primes congruent to 37 mod 61.at n=39A142835
• Expansion of g.f.: 1/(1 - x - 2*x^2 + x^3 + x^4 + 2*x^7 - 5*x^9 + 2*x^11 + x^14 + x^15 - 2*x^16 - x^17 + x^18).at n=21A147622
• Primes p such that A000041(p)+p are also prime numbers.at n=14A163151
• Primes p such that 2*p^5-+3 are also prime.at n=4A174368
• Primes p such that reversal(p) - 13 is a square.at n=22A176371
• Array read by antidiagonals: T(m,n) = Sum(1<=i<=m) i * ( n + 2(i-1) )!at n=9A211366
• Fibonacci with priority for primes: a(0)=0, a(1)=1, for n >= 2, a(n) = a(n-1) + a(k), where 0 < k <= n-2 is maximal index such that a(n-1) + a(k) is prime. If there is no such k, then a(n) = a(n-1) + a(n-2).at n=31A216231
• Primes congruent to 1 mod 59.at n=38A216315
• Primes whose base-3 representation also is the base-2 representation of a prime.at n=33A235265
• Sum of distinct terms of A002674: a(0) = 0, a(2n) = A255411(A153880(a(n))), a(2n+1) = 1+A255411(A153880(a(n))).at n=15A275959
• Collatz-2 (A063041) trajectory starting at 47.at n=10A280707