A057268 a(n-1)+k=a(n) => a(n)*k=a(n+1).

1, 3, 6, 18, 216, 42768, 1819863936, 3311826913612597248, 10968197499701667312529793029329125376, 120301356392461906290006219878693096559247086148184247242087281541542576128

Offset: 0

Author

Jonas Wallgren, Aug 22 2000

Keywords

• easy
• nonn

Comments

For +k and ^k see A057269. (Using *k and ^k gives another formulation of A014222. In this case the sequence could start 1,2 - see A014221.)

See the Comments section in A001696 as a connection to some sieving process. - Ctibor O. Zizka, Feb 13 2025

Crossrefs

Cf. A001696, A057269.

Programs

Mathematica

nxt[{a_,b_}]:={b,b(b-a)}; NestList[nxt,{1,3},9][[All,1]] (* Harvey P. Dale, Sep 05 2017 *)

Formula

a(0) = 1, a(1) = 3, for n >= 2, a(n) = a(n - 1)*(a(n - 1) - a(n - 2)). - Ctibor O. Zizka, Feb 13 2025

Extensions

More terms from Harvey P. Dale, Sep 05 2017