A373831 Numbers whose primorial base representation has alternating digit sum that is a multiple of 3.

0, 3, 8, 11, 13, 16, 18, 21, 26, 29, 31, 34, 36, 39, 44, 47, 49, 52, 54, 57, 62, 65, 67, 70, 72, 75, 80, 83, 85, 88, 90, 93, 98, 101, 103, 106, 108, 111, 116, 119, 121, 124, 126, 129, 134, 137, 139, 142, 144, 147, 152, 155, 157, 160, 162, 165, 170, 173, 175, 178, 180, 183, 188, 191, 193, 196, 198, 201, 206, 209, 212

Offset: 1

Author

Antti Karttunen, Jun 19 2024

Keywords

• nonn
• base

Examples

			A049345(3) = 11, and the alternating digit sum is A373605(3) = 1-1 = 0, and as zero is a multiple of 3, 3 is included in this sequence.
A049345(193) = 6201, and the alternating digit sum is (1+2)-(0+6) = -3, thus 193 is included in this sequence.
		

Links

• Antti Karttunen, Table of n, a(n) for n = 1..20020
• Index entries for sequences related to primorial base

Crossrefs

Cf. A049345, A373605, A373830 (characteristic function).

Programs

PARI

isA373831 = A373830;