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A338843
No prime digit is present in a(n) + a(n+1).
8
0, 1, 3, 5, 4, 2, 6, 8, 10, 9, 7, 11, 29, 12, 28, 13, 27, 14, 26, 15, 25, 16, 24, 17, 23, 18, 22, 19, 21, 20, 40, 41, 39, 30, 31, 33, 35, 34, 32, 36, 44, 37, 43, 38, 42, 46, 45, 49, 47, 51, 48, 50, 54, 52, 56, 53, 55, 59, 57, 61, 58, 60, 80, 64, 76, 65, 75, 66, 74, 67, 73, 68, 72, 69, 71, 70, 78, 62
OFFSET
1,3
COMMENTS
The prime digits are 2, 3, 5 and 7. This is the lexicographically earliest sequence of distinct nonnegative terms with this property and also a permutation of the nonnegative integers.
EXAMPLE
a(1) + a(2) = 0 + 1 = 1 (no prime digit is present);
a(2) + a(3) = 1 + 3 = 4 (no prime digit is present);
a(3) + a(4) = 3 + 5 = 8 (no prime digit is present); etc.
MATHEMATICA
Block[{a = {0}}, Do[Block[{k = 1}, While[Nand[FreeQ[a, k], NoneTrue[IntegerDigits@ Total[a[[-1]] + k], PrimeQ]], k++]; AppendTo[a, k]], {i, 2, 78}]; a] (* Michael De Vlieger, Nov 12 2020 *)
CROSSREFS
Cf. A202268 (no prime digits).
Cf. A338839, A338840, A338841, A338842, A338844, A338845, A338846 (variants on the same idea).
Sequence in context: A134892 A253074 A055266 * A075077 A196771 A266121
KEYWORD
nonn,look,base
AUTHOR
Eric Angelini and Carole Dubois, Nov 11 2020
STATUS
approved