OFFSET
1,2
COMMENTS
This is the lexicographically earliest sequence of distinct nonnegative terms with this property.
LINKS
Carole Dubois, Table of n, a(n) for n = 1..9999
EXAMPLE
a(1) + a(2) = 0 + 2 = 2 (no odd digit is present);
a(2) + a(3) = 2 + 4 = 6 (no odd digit is present);
a(3) + a(4) = 4 + 16 = 20 (no odd digit is present); etc.
MATHEMATICA
Block[{a = {0}}, Do[Block[{k = 2}, While[Nand[FreeQ[a, k], AllTrue[IntegerDigits@ Total[a[[-1]] + k], EvenQ]], k += 2]; AppendTo[a, k]], {i, 2, 71}]; a] (* Michael De Vlieger, Nov 12 2020 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Eric Angelini and Carole Dubois, Nov 11 2020
STATUS
approved