A360478 Least k such that the first n primes divide k and the next n primes divide k+1.

2, 174, 11010, 877590, 3576536040, 7300395162060, 8122095802580760, 15497422946114018910, 6949903578918639188850, 482875127106370562524140180, 2448313281623289989477792853630, 20024982066721727911275778517919720, 29200503600421680216708710172770859570

Offset

1,1

Links

Samuel Harkness, Table of n, a(n) for n = 1..175

Example

a(3) = 11010 because the first 3 primes {2, 3, 5} divide 11010 and the next 3 primes {7, 11, 13} divide 11011.

Mathematica

K = {}; For[n = 1, n <= 13, n++, R = Prime[Range[2 n]];
 A = R[[1 ;; n]]; t = Times @@ A; B = R[[n + 1 ;; 2 n]]; p = t + 1;
 For[b = 1, b <= n, b++, While[Mod[p, Part[B, b]] != 0, p += t];
  t *= Part[B, b]]; AppendTo[K, p - 1]]; Print[K]

Prog

(PARI) a(n)={my(p=primes(2*n)); lift(chinese(Mod(0, vecprod(p[1..n])), Mod(-1, vecprod(p[n+1..2*n]))))} \\ Andrew Howroyd, Feb 08 2023

Crossrefs

Cf. A069561.

Sequence in context: A139935 A281958 A172231 * A193638 A215123 A321634

Adjacent sequences: A360475 A360476 A360477 * A360479 A360480 A360481

Keyword

nonn

Author

Samuel Harkness, Feb 08 2023

Status

approved