A014889 n is equal to the number of 5s in all numbers <= n written in base 7.

761664, 817499, 817500, 817507, 817508, 819609, 823543, 1585207, 1641042, 1641043, 1641050, 1641051, 1643152, 1647086, 2408750, 2464585, 2464586, 2464593, 2464594, 2466695, 2470629, 3232293, 3288128, 3288129, 3288136, 3288137, 3290238, 3294172, 4055836, 4111671, 4111672, 4111679, 4111680, 4113781

Offset: 1

Author

Olivier Gérard

Keywords

• nonn
• base
• fini
• full

Links

• Index entries for linear recurrences with constant coefficients, signature (1, 0, 0, 0, 0, 0, 1, -1).

Crossrefs

Cf. A014778.

Programs

Mathematica

LinearRecurrence[{1,0,0,0,0,0,1,-1},{761664,817499,817500,817507,817508,819609,823543,1585207},34] (* Harvey P. Dale, Apr 14 2020 *)

Formula

a(n) = a(n-1) + a(n-7) - a(n-8) for 8 < n <= 34. - Chai Wah Wu, Jun 06 2016

Extensions

List proved complete by Hugo van der Sanden (cf. A014886).