20549

Properties

Appears in sequences

• Sums of 5 distinct powers of 4.at n=37A038473
• Base-8 palindromes that start with 5.at n=19A043025
• n*10^5-1, n*10^5-3, n*10^5-7 and n*10^5-9 are all prime.at n=5A064979
• Leading diagonal of triangle in A072467.at n=21A072468
• Primes which can be expressed as sum of distinct powers of 4.at n=27A077718
• Lesser of a twin-prime pair where both are expressible as the sum of two triangular numbers.at n=38A118638
• A106486-encodings of combinatorial games with value 2.at n=29A125995
• Primes congruent to 17 mod 59.at n=39A142744
• Primes p such that continued fraction of (1 + sqrt(p))/2 has period 15: primes in A146338.at n=31A146360
• Primes of form a^2+b^2 such that a^4+b^4 and a^8+b^8 are primes.at n=15A182313
• Least prime p such that p*10^n-1, p*10^n-3, p*10^n-7 and p*10^n-9 are all prime.at n=4A243411
• Subtract 1 from the terms of A256407.at n=34A256410
• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 630", based on the 5-celled von Neumann neighborhood.at n=7A267268
• Primes 8k + 5 preceding the maximal gaps in A269513.at n=12A269514
• Sum of the prime parts in the partitions of n into 7 parts.at n=35A309468
• Primes p such that p+2, (p+1)||p and (p+1)||(p+2) are primes (where || denotes concatenation in base 10).at n=26A309934
• Expansion of Sum_{k>=0} x^(k^2) / Product_{j=1..k} (1 - x^j)^j.at n=39A318771
• Prime numbersat n=2319