A093552 a(n) is the smallest number m such that m-k is product of k+1 primes for k=0,1,2,...,n.

2, 5, 47, 107, 71999, 392279, 305778479, 24405534719, 899133243623

Offset

0,1

Comments

Each term of this sequence is prime.

Links

Table of n, a(n) for n=0..8.

Example

a(5)=392279 because:
392279 is prime;
392279-1 = 2*196139;
392279-2 = 3*229*571;
392279-3 = 2*2*281*349;
392279-4 = 5*5*13*17*71;
392279-5 = 2*3*3*19*31*37;
392279 is the smallest number m such that m-k is product of k+1 primes for k=0,1,2,3,4 & 5.

Mathematica

Table[m = 1; While[Table[Plus @@ Last /@ FactorInteger[Prime[m] - k], {k, 0, n}] != Range[1, n + 1], m++]; Prime[m], {n, 0, 5}] (* Robert Price, Jun 09 2019 *)

Crossrefs

Cf. A072664, A072875, A086560.

Sequence in context: A041729 A078665 A163666 * A060808 A099658 A357246

Adjacent sequences: A093549 A093550 A093551 * A093553 A093554 A093555

Keyword

nonn,more

Author

Farideh Firoozbakht, Apr 14 2004

Extensions

a(6) corrected by Mike Oakes, Jun 20 2012

a(7) from Zak Seidov, Apr 23 2017

a(8) from Giovanni Resta, Apr 27 2017

Status

approved