A373607 Sum of the odd-indexed digits in the primorial base representation (A049345) of n.

0, 0, 1, 1, 2, 2, 0, 0, 1, 1, 2, 2, 0, 0, 1, 1, 2, 2, 0, 0, 1, 1, 2, 2, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 3, 3, 1, 1, 2, 2, 3, 3, 1, 1, 2, 2, 3, 3, 1, 1, 2, 2, 3, 3, 1, 1, 2, 2, 3, 3, 2, 2, 3, 3, 4, 4, 2, 2, 3, 3, 4, 4, 2, 2, 3, 3, 4, 4, 2, 2, 3, 3, 4, 4, 2, 2, 3, 3, 4, 4, 3, 3, 4, 4, 5, 5, 3, 3, 4, 4, 5, 5, 3, 3, 4, 4

Offset

0,5

Links

Antti Karttunen, Table of n, a(n) for n = 0..16170

Index entries for sequences related to primorial base

Formula

a(n) = A276150(n) - A373606(n).

a(n) = A373606(n) - A373605(n).

Example

A049345(85) = 2401, and the sum of digits at the odd positions  (with the rightmost digit having index 0) is 0+2 = 2, thus a(85) = 2.

Prog

(PARI) A373607(n) = { my(p=2, i=0, s=0); while(n, if(i%2, s += (n%p)); n = n\p; p = nextprime(1+p); i = !i); (s); };

Crossrefs

Cf. A049345, A276150, A373605, A373606.

Sequence in context: A050605 A060571 A131555 * A293209 A318753 A318757

Adjacent sequences: A373604 A373605 A373606 * A373608 A373609 A373610

Keyword

nonn

Author

Antti Karttunen, Jun 18 2024

Status

approved