A387775 a(1) = 2; for n > 1, a(n) = a(n-1)*prime(n) if a(n-1) <= prime(n), otherwise a(n) = a(n-1) mod prime(n).

2, 6, 1, 7, 77, 12, 204, 14, 322, 3, 93, 19, 779, 5, 235, 23, 1357, 15, 1005, 11, 803, 13, 1079, 11, 1067, 57, 5871, 93, 10137, 80, 10160, 73, 10001, 132, 19668, 38, 5966, 98, 16366, 104, 18616, 154, 29414, 78, 15366, 43, 9073, 153, 34731, 152, 35416, 44

Offset

1,1

Links

Ruud H.G. van Tol, Table of n, a(n) for n = 1..10000

Example

For n = 5, a(4) = 7 and prime(5) = 11, so a(4) <= prime(5) and a(5) = a(4) * prime(5) = 77.
For n = 6, a(5) = 77 and prime(6) = 13, so a(5) > prime(6) and a(6) = a(5) mod prime(6) = 12.

Mathematica

FoldList[If[# <= #2, #*#2, Mod[#, #2]] &, Prime[Range[100]]] (* Paolo Xausa, Sep 14 2025 *)

Prog

(PARI) lista(nn) = my(t=1, p); vector(nn, n, t=if(t<=(p=prime(n)), t*p, t%p))

Crossrefs

Cf. A382619.

Sequence in context: A021386 A201936 A019679 * A382619 A104457 A155832

Adjacent sequences: A387772 A387773 A387774 * A387776 A387777 A387778

Keyword

nonn

Author

Ruud H.G. van Tol, Sep 08 2025

Status

approved