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A373839
Numbers k such that k and A276150(k) are both multiples of 3, where A276150 is the digit sum in the primorial base.
4
0, 9, 18, 27, 33, 42, 51, 66, 75, 84, 90, 99, 108, 117, 123, 132, 141, 156, 165, 174, 180, 189, 198, 207, 213, 222, 231, 246, 255, 264, 270, 279, 288, 297, 303, 312, 321, 336, 345, 354, 360, 369, 378, 387, 393, 402, 411, 426, 435, 444, 450, 459, 468, 477, 483, 492, 501, 516, 525, 534, 540, 549, 558, 567, 573, 582
OFFSET
1,2
COMMENTS
If x and y are terms and if A329041(x,y) = 1 (i.e., when adding x and y together will not generate any carries in the primorial base), then x+y is also a term. This follows from the quasi-exponential nature of A276086 and because A373837 is a multiplicative semigroup. See also A373599.
PROG
(PARI) isA373839 = A373838;
CROSSREFS
Intersection of A008585 and A373841.
Indices of multiples of 3 in A373833.
Cf. A276150, A329041, A373838 (characteristic function).
Cf. also A373599, A373837.
Sequence in context: A359225 A037337 A119310 * A037993 A044849 A282149
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Jun 19 2024
STATUS
approved