A086929 a(1) = 1, a(n) = n times (the digit reversal of the (n-1)-th partial sum).

1, 2, 9, 84, 345, 864, 35217, 180504, 5586408, 43430850, 530676234, 9780239700, 1055666381913, 18372986892414, 818136466402365, 314063593211808, 139031163059145687, 9080662161749058738, 64855015790195124351

Offset

1,2

Links

Robert Israel, Table of n, a(n) for n = 1..438

Example

a(5) = 5*(reversal of (1+2+9+84)) = 5*(rev(96)) = 5*69 = 345.

Maple

digrev:= proc(n) local L, i;
  L:= convert(n, base, 10);
  add(L[-i]*10^(i-1), i=1..nops(L))
end proc:
A[1]:= 1: S:= 1:
for n from 2 to 20 do A[n]:= n*digrev(S); S:= S + A[n] od:
seq(A[i], i=1..20); # Robert Israel, Jun 02 2020

Crossrefs

Sequence in context: A354045 A296581 A069234 * A193466 A354310 A262011

Adjacent sequences: A086926 A086927 A086928 * A086930 A086931 A086932

Keyword

base,nonn

Author

Amarnath Murthy, Sep 19 2003

Extensions

More terms from Ray Chandler, Sep 23 2003

Status

approved