19501

Properties

Appears in sequences

• a(n) = (1/16)*( binomial(4*n, 2*n) - (-1)^n*binomial(2*n, n) + (1-(-1)^n)*binomial(2*n, n)^2 ).at n=5A037980
• Sums of 5 distinct powers of 5.at n=18A038477
• Primes which can be expressed as sum of distinct powers of 5.at n=10A077719
• Prime numbers that are 2 less than a prime-indexed odd triangular number or 1 more than a prime-indexed even triangular number.at n=27A096333
• a(n) = n^3 - 7*n + 7.at n=26A106734
• G.f.: 1/(1 - x - 25*x^2).at n=6A122999
• Primes congruent to 50 mod 53.at n=40A142580
• Primes congruent to 31 mod 59.at n=36A142758
• Primes congruent to 42 mod 61.at n=34A142840
• Primes of the form 250n + 1.at n=20A179231
• Prime-generating polynomial: a(n) = 16*n^2 - 292*n + 1373.at n=44A181969
• Primes of the form 8*k^2 + 6*k - 1 for positive k.at n=27A187677
• Primes of the form 6n^2 + 7.at n=24A201601
• Primes p such that, for p < q < r three consecutive primes, p + 2q + 2r, 2p + q + 2r and 2p + 2q + r are all primes.at n=3A216262
• a(n) = 25*n*(n + 1)/2 + 1.at n=39A262221
• Centered 25-gonal primes.at n=9A276264
• Smallest k such that both of the consecutive Woodall numbers A003261(k) and A003261(k+1) are divisible by A014662(n), the n-th prime p with even order of 2 mod p.at n=30A287145
• a(n) is the smallest prime p = prime(k) such that A300845(k) = prime(n), or 0 if no such k exists.at n=38A300854
• Triangle read by rows: T(m,n) is the label of the largest square that an (m,n)-leaper (a generalization of a chess knight) reaches before it can no longer move, starting on a board with squares spirally numbered, starting at 1; 1 <= n < m. Each move is to the lowest-numbered unvisited square.at n=41A306197
• Primes p such that A001175(p) = (p-1)/6.at n=22A308791