Members of the sequence defined by the recurrence J(0)=0, J(1)=1 and J(n-1) = J(n-1) + 2⋅J(n-2). more
The Jacobsthal numbers up to 10
15 :
1,
3,
5,
11,
21,
43,
85,
171,
341,
683,
1365,
2731,
5461,
10923,
21845,
43691,
87381,
174763,
349525,
699051,
1398101,
2796203,
5592405,
11184811,
22369621,
44739243,
89478485,
178956971,
357913941,
715827883,
1431655765,
2863311531,
5726623061,
11453246123,
22906492245,
45812984491,
91625968981,
183251937963,
366503875925,
733007751851,
1466015503701,
2932031007403,
5864062014805,
11728124029611,
23456248059221,
46912496118443,
93824992236885,
187649984473771,
375299968947541,
750599937895083.
Distribution of the remainders when the numbers in this family are divided by n=2, 3,..., 11. (I took into account 10000 values, from 1 to 1.33⋅103010).
n\r | 0 | 1 |
2 | 0 | 10000 | 2 |
3 | 3333 | 3333 | 3334 | 3 |
4 | 0 | 5000 | 0 | 5000 | 4 |
5 | 2500 | 5000 | 0 | 2500 | 0 | 5 |
6 | 0 | 3333 | 0 | 3333 | 0 | 3334 | 6 |
7 | 1666 | 3333 | 0 | 1667 | 1667 | 1667 | 0 | 7 |
8 | 0 | 1 | 0 | 5000 | 0 | 4999 | 0 | 0 | 8 |
9 | 1111 | 1111 | 1111 | 1112 | 1111 | 1111 | 1110 | 1111 | 1112 | 9 |
10 | 0 | 5000 | 0 | 2500 | 0 | 2500 | 0 | 0 | 0 | 0 | 10 |
11 | 2000 | 2000 | 0 | 1000 | 0 | 1000 | 1000 | 0 | 1000 | 0 | 2000 |
A pictorial representation of the table above
Imagine to divide the members of this family by a number n and compute the remainders. Should they be uniformly distributed, each remainder from 0 to n-1 would be obtained in about (1/n)-th of the cases. This outcome is represented by a white square. Reddish (resp. bluish) squares represent remainders which appear more (resp. less) frequently than 1/n.