A162192 Triangle read by rows in which row n lists the divisors of n, prime(n), the consecutive composites that are greater than prime(n), and prime (n+1), but row 0 is formed by 1 and 2.

1, 2, 1, 2, 3, 1, 2, 3, 4, 5, 1, 3, 5, 6, 7, 1, 2, 4, 7, 8, 9, 10, 11, 1, 5, 11, 12, 13, 1, 2, 3, 6, 13, 14, 15, 16, 17, 1, 7, 17, 18, 19, 1, 2, 4, 8, 19, 20, 21, 22, 23, 1, 3, 9, 23, 24, 25, 26, 27, 28, 29, 1, 2, 5, 10, 29, 30, 31

Offset

0,2

Comments

See also A162190, a sequence with a similar structure.

Links

Table of n, a(n) for n=0..67.

Omar E. Pol, Illustration: Divisors and pi(x)

Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos

Example

Triangle begins:
1,(2);
1,(2),(3);
1,.2.,(3),4,(5);
1,.....3,...(5),6,(7);
1,.2,.....4,......(7),8,.9,10,(11);
1,...........5,...............(11),12,(13);
1,.2,..3,.......6,....................(13),14,15,16,(17);
1,.................7,...............................(17),18,(19);
1,.2,.....4,..........8,....................................(19),20,21,22,(23);

Crossrefs

Cf. A000005, A000040, A000720, A027750, A018253, A160811, A160812, A161205, A161344, A161345, A161424, A006446, A161827, A161828, A161835, A162190.

Sequence in context: A037125 A194029 A194055 * A329795 A329794 A238954

Adjacent sequences: A162189 A162190 A162191 * A162193 A162194 A162195

Keyword

easy,nonn,tabf

Author

Omar E. Pol, Jun 30 2009

Status

approved