A374363 - OEIS

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A374363

a(n) is the greatest term t <= n of A005836 such that n - t also belongs to A005836.

0, 1, 1, 3, 4, 4, 3, 4, 4, 9, 10, 10, 12, 13, 13, 12, 13, 13, 9, 10, 10, 12, 13, 13, 12, 13, 13, 27, 28, 28, 30, 31, 31, 30, 31, 31, 36, 37, 37, 39, 40, 40, 39, 40, 40, 36, 37, 37, 39, 40, 40, 39, 40, 40, 27, 28, 28, 30, 31, 31, 30, 31, 31, 36, 37, 37, 39, 40

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

OFFSET

0,4

COMMENTS

To compute a(n): in the ternary expansion of n, 2's by 1's.

LINKS

Rémy Sigrist, Table of n, a(n) for n = 0..6560

FORMULA

a(n) = T(n, A120880(k)-1).

a(n) = n - A374362(n).

a(n) <= n with equality iff n belongs to A005836.

a(n) = A005836(1+A289831(n)).

EXAMPLE

The first terms, in decimal and in ternary, are:

n a(n) ter(n) ter(a(n))

-- ---- ------ ---------

0 0 0 0

1 1 1 1

2 1 2 1

3 3 10 10

4 4 11 11

5 4 12 11

6 3 20 10

7 4 21 11

8 4 22 11

9 9 100 100

10 10 101 101

11 10 102 101

12 12 110 110

13 13 111 111

14 13 112 111

15 12 120 110

PROG

(PARI) a(n) = fromdigits(apply(d -> [0, 1, 1][1+d], digits(n, 3)), 3)

CROSSREFS

Cf. A005836, A120880, A289831, A374361, A374362.

Sequence in context: A276865 A253718 A350188 * A295570 A035004 A222290

Adjacent sequences: A374360 A374361 A374362 * A374364 A374365 A374366

KEYWORD

nonn,base

AUTHOR

Rémy Sigrist, Jul 06 2024

STATUS

approved