A079355 a(1) = 1; a(n) = a(n-1)-3 if n is already in the sequence, a(n) = a(n-1)+4 otherwise.

1, 5, 9, 13, 10, 14, 18, 22, 19, 16, 20, 24, 21, 18, 22, 19, 23, 20, 17, 14, 11, 8, 5, 2, 6, 10, 14, 18, 22, 26, 30, 34, 38, 35, 32, 36, 40, 37, 41, 38, 35, 39, 43, 47, 51, 55, 52, 56, 60, 64, 61, 58, 62, 66, 63, 60, 64, 61, 65, 62, 59, 56, 53, 50, 47, 44, 48, 52, 56, 60, 64, 68

Offset: 1

Author

Benoit Cloitre, Feb 14 2003

Keywords

• nonn
• hear

Crossrefs

Cf. A079357.

Formula

a(n) = n+b(n)-22 where b(n) is the 42-periodic sequence (22, 25, 28, 31, 27, 30, 33, 36, 32, 28, 31, 34, 30, 26, 29, 25, 28, 24, 20, 16, 12, 8, 4, 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 23, 19, 22, 25, 21, 24, 20, 16, 19)