A162520 Pairs (i,j) of positive integers where j<10.

1, 1, 1, 2, 1, 3, 1, 4, 1, 5, 1, 6, 1, 7, 1, 8, 1, 9, 2, 1, 2, 2, 2, 3, 2, 4, 2, 5, 2, 6, 2, 7, 2, 8, 2, 9, 3, 1, 3, 2, 3, 3, 3, 4, 3, 5, 3, 6, 3, 7, 3, 8, 3, 9, 4, 1, 4, 2, 4, 3, 4, 4, 4, 5, 4, 6, 4, 7, 4, 8, 4, 9, 5, 1, 5, 2, 5, 3, 5, 4, 5, 5, 5, 6, 5, 7, 5, 8, 5, 9, 6, 1, 6, 2, 6, 3, 6, 4, 6, 5, 6, 6

Offset

1,4

Comments

Note that first 144 pairs, (1,1) to (16,9), are related to the influenza A virus which causes influenza in birds and some mammals. The influenza A virus has 144 subtypes: H1N1, H1N2, H1N3, H1N4, H1N5, H1N6, H1N7, H1N8, H1N9, H2N1, H2N2, ..., H16N8 and H16N9.

Links

Table of n, a(n) for n=1..102.

Crossrefs

Sequence in context: A336514 A358851 A249009 * A342703 A249068 A308073

Adjacent sequences: A162517 A162518 A162519 * A162521 A162522 A162523

Keyword

easy,nonn

Author

Omar E. Pol, Jul 06 2009

Status

approved