A008467 a(n) = n OR n^2 (applied to ternary expansions).

1, 5, 12, 16, 26, 42, 52, 71, 90, 100, 122, 147, 178, 206, 231, 259, 296, 342, 370, 401, 453, 484, 539, 591, 646, 701, 756, 784, 842, 930, 961, 1025, 1095, 1186, 1259, 1332, 1369, 1445, 1524, 1609, 1691, 1770, 1852, 1943, 2070, 2152, 2237, 2316, 2401, 2510

Offset: 1

Author

Olivier Gérard

Keywords

• base
• nonn
• easy

Comments

OR(a, b) = max(a, b) for ternary digits a and b. - Sean A. Irvine, Mar 29 2018

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007745, A008468, A008469.

Programs

Maple

a:= proc(n) option remember; local g, h, i, r;
      g, h, r:= n, n^2, 0; for i from 0 while h>0 do
      r:= r + 3^i * max(irem(g, 3, 'g'), irem(h, 3, 'h')) od; r
    end:
seq(a(n), n=1..140);  # Alois P. Heinz, Mar 29 2018

Mathematica

(* program should not be used to extend this sequence *)
b=3; d=9; Mb=Array[ b^(d-#)&, d ]; Map[ Plus@@(Mb*#)&, Array[ Max /@ Transpose[ {IntegerDigits[ #, b, d ], IntegerDigits[ #^2, b, d ]} ]&, 140 ] ]