A060730 a(n) = a(n-1) + a(n - 1 minus the number of terms of a(k) == n (mod 3) so far).

1, 2, 3, 5, 7, 12, 17, 22, 34, 41, 53, 87, 109, 131, 184, 218, 252, 361, 414, 501, 632, 763, 894, 1112, 1330, 1548, 1909, 2161, 2575, 3207, 3568, 4331, 5225, 5726, 6489, 7819, 8582, 9694, 11855, 12967, 14515, 18083, 19413, 21574, 26799, 28708, 32276

Offset

1,2

Links

Table of n, a(n) for n=1..47.

Example

a(5) = a(4) + a(4 - the number of terms congruent to 2 (mod 3) so far) = a(4) + a(4-2) = 5 + 2 = 7.

Mathematica

m[ 1 ] = 1; m[ 2 ] = 2; m[ 3 ] = 3; m[ n_Integer ] := m[ n ] = Block[ {a = b = c = 0}, Do[ Switch[ Mod[ m[ k ], 3 ], 0, a++, 1, b++, 2, c++ ], {k, 1, n - 1} ]; Switch[ Mod[ n, 3 ], 0, m[ n - 1 ] + m[ n - 1 - a ], 1, m[ n - 1 ] + m[ n - 1 - b ], 2, m[ n - 1 ] + m[ n - 1 - c ] ] ]; Table[ m[ n ], {n, 1, 50} ]

Crossrefs

Sequence in context: A319769 A326083 A027959 * A308928 A308992 A326468

Adjacent sequences: A060727 A060728 A060729 * A060731 A060732 A060733

Keyword

nonn

Author

Robert G. Wilson v, Apr 22 2001

Status

approved