A121260 Beginning with a(1)=0, take a(n) to be the smallest number not equal to the product of two consecutive (not distinct) earlier terms.

0, 0, 1, 1, 2, 2, 3, 3, 5, 5, 7, 7, 8, 8, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 24, 26, 26, 27, 27, 28, 28, 29, 29, 30, 30, 31, 31, 32, 32, 33, 33, 34, 34, 36, 36, 37, 37, 38, 38, 39, 39, 40, 40, 41, 41, 42, 42

Offset

1,5

Comments

Apparently the definition is: a(1)=0. For even n, a(n)=a(n-1). For odd n, a(n) is the smallest value > a(n-1) which is not equal to some product a(i)*a(i-1) of two consecutive earlier terms. - R. J. Mathar, Jun 21 2021

Links

Table of n, a(n) for n=1..74.

Crossrefs

Cf. A121229.

Sequence in context: A341462 A035031 A035032 * A121261 A085885 A309685

Adjacent sequences: A121257 A121258 A121259 * A121261 A121262 A121263

Keyword

easy,nonn

Author

Giovanni Teofilatto, Aug 23 2006

Extensions

Offset corrected. - R. J. Mathar, Jun 20 2021

Status

approved