A095238 a(1) = 1, a(n) = n*(sum of all previous terms mod n).

1, 2, 0, 12, 0, 18, 35, 32, 9, 90, 11, 72, 117, 98, 30, 240, 34, 162, 247, 200, 63, 462, 69, 288, 425, 338, 108, 756, 116, 450, 651, 512, 165, 1122, 175, 648, 925, 722, 234, 1560, 246, 882, 1247, 968, 315, 2070, 329, 1152, 1617, 1250, 408, 2652, 424, 1458, 2035

Offset: 1

Author

Amarnath Murthy, Jun 15 2004

Keywords

• nonn

Comments

An open question is whether the sequence contains zeros except for the 3rd and the 5th number. I checked this up to a(10000), which happens to be 99990000. - Johan Claes, Jun 16 2004

Examples

			a(6) = 6*((1 + 2 + 0 + 12 + 0) mod 6) = 18.
		

Crossrefs

Cf. A074143.

Programs

Maple

A095238:=proc(n) option remember; n*(add(A095238(i),i=1..n-1) mod n) end: A095238(1):=1: seq(A095238(n),n=1..100);

Mathematica

a[1] = 1; a[n_] := a[n] = n*Mod[Sum[a[i], {i, n - 1}], n]; Table[ a[n], {n, 55}] (* Robert G. Wilson v, Jun 16 2004 *)

PARI

a=vector(1000);a[1]=1;for(i=2,1000,a[i]=i*lift(Mod(sum(j=1,i-1,a[j]),i)))

Formula

Appears to satisfy a linear recurrence with characteristic polynomial (1+x)(1+x^3)^2(1-x^3)^3 (checked up to n = 10^4). - Ralf Stephan, Dec 04 2004

Extensions

More terms from Alec Mihailovs (alec(AT)mihailovs.com), Robert G. Wilson v and Johan Claes, Jun 16 2004