A160943 - OEIS

A160943

a(n) = n + digital sum(n-1) + digital sum(n+1).

3, 6, 9, 12, 15, 18, 21, 24, 18, 21, 15, 18, 21, 24, 27, 30, 33, 36, 30, 33, 27, 30, 33, 36, 39, 42, 45, 48, 42, 45, 39, 42, 45, 48, 51, 54, 57, 60, 54, 57, 51, 54, 57, 60, 63, 66, 69, 72, 66, 69, 63, 66, 69, 72, 75, 78, 81, 84, 78, 81, 75, 78, 81, 84, 87, 90, 93, 96, 90, 93

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..70.

FORMULA

a(n) = n + A007953(n-1) + A007953(n+1)

EXAMPLE

a(8) = 8 +ds(7) +ds(9) = 7+8+9 = 24;

a(15) = 15+ds(14)+ds(16) = 15+5+7 = 27;

a(26) = 26+ds(25)+ds(27) = 26+7+9 = 42.

MATHEMATICA