A215451 a(0)=1, a(n) = (sum of previous terms) mod (a(n-1)+n).

1, 1, 2, 4, 0, 3, 2, 4, 5, 8, 12, 19, 30, 5, 1, 1, 13, 21, 15, 11, 3, 17, 22, 20, 0, 20, 10, 28, 54, 0, 2, 4, 14, 23, 33, 0, 12, 28, 52, 45, 35, 48, 88, 61, 42, 36, 35, 70, 16, 1, 8, 41, 3, 21, 0, 5, 18, 23, 43, 17, 1, 41, 65, 111, 149, 25, 1, 53, 29, 63, 98, 102, 154, 5

Offset: 0

Author

Alex Ratushnyak, Aug 11 2012

Keywords

• nonn

Comments

Indices of 0's: 4, 24, 29, 35, 54, 267, 5284, 17827, 43631, 120871, 843813, 1854903, 2226536, 4208775, 5525594, ...

Indices of 1's: 0, 1, 14, 15, 49, 60, 66, 116, 331, 6053, 23760, 288502, 496670, 4281666, ...

Indices such that a(n)=n: 1, 2, 22, 315, 1172, 1441, 1846, 2140, 47376, 593870, 16538298, 111824649, 565597433, 791186876, ...

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A094405, A066910, A215452.

Programs

Mathematica

nxt[{n_,t_,a_}]:=Module[{c=Mod[t,a+n+1]},{n+1,t+c,c}]; NestList[nxt,{0,1,1},80][[All,3]] (* Harvey P. Dale, Dec 30 2017 *)

Python

s = a = 1
for n in range(1,333):
    print(a, end=', ')
    a = s % (a+n)
    s += a

Formula

a(0)=1, a(n) = (a(0)+...+a(n-1)) mod (a(n-1)+n).