A216998 Digit sum of n*7 mod 7.

0, 5, 3, 3, 1, 6, 6, 4, 2, 0, 0, 5, 3, 3, 6, 4, 4, 2, 0, 5, 5, 3, 1, 1, 6, 4, 4, 2, 5, 3, 3, 1, 6, 6, 4, 2, 2, 0, 5, 3, 3, 1, 4, 4, 2, 0, 0, 5, 3, 1, 1, 6, 4, 4, 2, 0, 0, 3, 1, 6, 6, 4, 2, 2, 0, 5, 5, 3, 1, 6, 6, 2, 0, 0, 5, 3, 3, 1, 6, 4, 4, 2, 0, 0, 5, 1, 1, 6

Offset: 1

Author

Jon Perry, Sep 22 2012

Keywords

• nonn
• base

Comments

Zeros correspond to A216994.

Examples

			a(8) corresponds to the digit sum of 56, which is 11, mod 7, so a(8)=4.
		

Crossrefs

Cf. A216994, A216995, A216996, A216997, A217009.

Programs

JavaScript

function sumarray(arr) {
t=0;
for (i=0;i
				

Mathematica

Table[Mod[Total[IntegerDigits[7*n]], 7], {n, 100}] (* T. D. Noe, Sep 24 2012 *)