A178544 a(n) are such that n or one of its substrings is divisible by every integer from 1 to a(n).

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

Offset

1,2

Comments

Positions of records 1,2,6,12,45,54,56,... are terms in A177834 (with repetitions).

Links

Table of n, a(n) for n=1..105.

Example

a(56)=8 because divisors of 56 are d1={1,2,4,7,8,14,28,56},
divisors of 5 are d2={1, 5}, divisors of 6 are d3={1,2,3,6},
and union of d1, d2, d3 gives 8 subsequent integers 1..8 (14,28,.. not counted).

Mathematica

Table[id=IntegerDigits[n]; FLA=Flatten[Table[Partition[id, k, 1],
{k, Length[id]}], 1]; fd = Complement[Union[FromDigits /@ FLA], {0}];
dv=Union[Flatten[Divisors /@ fd]]; Complement[Range[100], dv][[1]]-1, {n, 10^3}]

Crossrefs

A177834.

Sequence in context: A232098 A055874 A195155 * A161506 A066451 A328048

Adjacent sequences: A178541 A178542 A178543 * A178545 A178546 A178547

Keyword

base,nonn

Author

Zak Seidov, May 29 2010

Status

approved