Question

A Diginacci sequence is created as follows.

• The first two terms are any positive whole numbers.
• Each of the remaining terms is the sum of the digits of the previous
two terms.
For example, starting with 5 and 8 the Diginacci sequence is
5, 8, 13, 12, 7, 10,...
The calculations for this example are
5+ 8 = 13, 8 + 1 + 3 = 12, 1+ 3 +1+ 2 = 7,1 + 2 + 7 = 10.
a) List the first 26 terms of the Diginacci sequence above.
b) Find, with explanation, two starting terms for a Diginacci sequence
so that its 2021st term is 11.
C) Find, with explanation, a Diginacci sequence that has no term equal
to 11
d) Find, with explanation, a sequence with two different starting terms
which contains five consecutive terms that are even and not all identical

Answer 1

a)

Answer:

5, 8, 13, 12, 7, 10, 8, 9, 17, 17, 16, 15, 13, 10, 5, 6, 11, 8, 10, 9, 10, 10, 2, 3, 5, 8

Step-by-step explanation:

Diginacci Sequence

5+8=13, 8+1=9, 1+3+1+2=7, 1+2+7=10, 7+1+0=8, 1+0+8=9, 8+9=17, 9+1+7=17