A136306 a(n) = a(n-1)*(10^K) + n*a(n-1); a(0)=1; K=floor(log_10 (n*a(n-1))).

1, 2, 6, 78, 8112, 81160560, 8116056486963360, 81160564869633656812395408743520, 8116056486963365681239540874352649284518957069254499163269948160

Offset

0,2

Comments

Sequence generalized :

a(n)=[a(n-1)*B^F(a(n-1),n)]+G(a(n-1),n); a(0)=1; F(t),G(t)integer functions.

Links

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

Formula

a(n)=a(n-1)*(10^K) + n + a(n-1); a(0)=1; K=floor(log_10 n + a(n-1)) + 1.

Maple

A136306 := proc(n)
    option remember;
    local k ;
    if n = 0 then
        1;
    else
        if n*procname(n-1) < 1 then
            k := 0;
        else
            k := floor(log[10](n*procname(n-1))) ;
        end if ;
        procname(n-1)*(n+10^k)  ;
    end if;
end proc:
seq(A136306(n), n=0..10) ; # R. J. Mathar, Jun 19 2021

Prog

(PARI) a(n) = if (n==0, 1, my(x=a(n-1), K=log(n*x)\log(10)); x*(10^K) + n*x); \\ Michel Marcus, Mar 16 2022

Crossrefs

Sequence in context: A262279 A327052 A231508 * A274825 A376059 A376061

Adjacent sequences: A136303 A136304 A136305 * A136307 A136308 A136309

Keyword

easy,nonn

Author

Ctibor O. Zizka, Mar 22 2008

Extensions

Offset corrected by R. J. Mathar, Jun 19 2021

More terms from Michel Marcus, Mar 16 2022

Status

approved