A338840 No even digit is present in a(n) + a(n+1).

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 21, 12, 19, 14, 17, 16, 15, 18, 13, 20, 11, 22, 29, 24, 27, 26, 25, 28, 23, 30, 41, 32, 39, 34, 37, 36, 35, 38, 33, 40, 31, 42, 49, 44, 47, 46, 45, 48, 43, 50, 61, 52, 59, 54, 57, 56, 55, 58, 53, 60, 51, 62, 69, 64, 67, 66, 65, 68, 63, 70, 81, 72, 79, 74, 77, 76, 75, 78, 73

Offset

1,3

Comments

This is the lexicographically earliest sequence of distinct nonnegative terms with this property and also a permutation of the nonnegative integers.

Links

Carole Dubois, Table of n, a(n) for n = 1..5001

Index entries for sequences that are permutations of the nonnegative integers

Example

a(1) + a(2) = 0 + 1 = 1 (no even digit is present);
a(2) + a(3) = 1 + 2 = 3 (no even digit is present);
a(3) + a(4) = 2 + 3 = 5 (no even digit is present);
...
a(6) + a(7) = 5 + 6 = 11 (no even digit is present); etc.

Mathematica

Block[{a = {0}}, Do[Block[{k = 1}, While[Nand[FreeQ[a, k], NoneTrue[IntegerDigits@ Total[a[[-1]] + k], EvenQ]], k++]; AppendTo[a, k]], {i, 2, 80}]; a] (* Michael De Vlieger, Nov 12 2020 *)

Crossrefs

Cf. A014261 (no even digits).

Cf. A338839, A338841, A338842, A338843, A338844, A338845, A338846 (variants on the same idea).

Sequence in context: A248651 A306361 A377903 * A068861 A341935 A256079

Adjacent sequences: A338837 A338838 A338839 * A338841 A338842 A338843

Keyword

base,nonn

Author

Eric Angelini and Carole Dubois, Nov 11 2020

Status

approved