A120763 a(1) = 2. a(n) = a(n-1)*(largest prime occurring earlier in the sequence) - 1.

2, 3, 8, 23, 528, 12143, 147452448, 1790515076063, 21742224568633008, 264015832936910616143, 3205944259352905611824448, 38929781141322332844384272063, 472724332399077087729358215661008, 5740291568321993076297596812771620143

Offset

1,1

Links

Table of n, a(n) for n=1..14.

Example

Among the first 4 terms of the sequence, 23 is the largest prime. So a(5) = a(4)*23 -1 = 23*23 -1 = 528.

Prog

(PARI) {m=13; print1(a=2, ", "); v=[a]; for(n=2, m, b=a; v=vecsort(v); j=#v; a=0; while(a<1, k=v[j]; if(isprime(k), print1(a=b*k-1, ", "); v=concat(v, a), j--)))} \\ Klaus Brockhaus, Aug 17 2006

Crossrefs

Cf. A120762.

Sequence in context: A365118 A032096 A301462 * A120708 A327009 A271269

Adjacent sequences: A120760 A120761 A120762 * A120764 A120765 A120766

Keyword

nonn,changed

Author

Leroy Quet, Jul 03 2006

Extensions

More terms from Klaus Brockhaus, Aug 17 2006.

a(14) added by Robert C. Lyons, Nov 16 2024.

Status

approved