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A242298 Once a number in this sequence is divisible by all numbers 1 to m, subsequent terms are constrained to have the same property; choose the smallest permissible number that is greater than the previous term. 0
1, 2, 4, 6, 12, 24, 36, 48, 60, 120, 180, 240, 300, 360, 420, 840, 1680, 2520, 5040, 7560, 10080, 12600, 15120, 17640, 20160, 22680, 25200, 27720, 55440, 83160, 110880, 138600, 166320, 194040, 221760, 249480, 277200, 304920, 332640, 360360, 720720, 1441440 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

All terms from A095848 belong to this sequence.

LINKS

Table of n, a(n) for n=1..42.

EXAMPLE

After 6, none of 7,8,9,10 or 11 are in the sequence since they are not divisible by 1,2 and 3 as 6 is. 12 qualifies, but is now divisible by 1,2,3 and 4, adding a new constraint on subsequent terms.

After 24, 30 is not in the sequence because 24 is divisible by all numbers from 1 to 4 and 30 is not divisible by 4. But 36, which is divisible by all of 1 through 4, qualifies.

As an irregular table, the n-th row consists of all numbers divisible by A051451(n) but not by A051451(n+1). - Tom Edgar, May 22 2014

PROG

(PARI) consecd(a) = {d = divisors(a); for (i=2, #d, if (d[i] - d[i-1] > 1, return(i-1)); ); return(a); }

findnext(a) = {nconsd = consecd(a); na = a + 1; while (consecd(na) < nconsd, na++); na; }

lista(nn) = {a = 1; print1(a, ", "); for (n=1, nn, a = findnext(a); print1(a, ", "); ); } \\ Michel Marcus, May 11 2014

CROSSREFS

Cf. A051451, A080765.

Sequence in context: A141551 A181804 A094348 * A002182 A077006 A166981

Adjacent sequences:  A242295 A242296 A242297 * A242299 A242300 A242301

KEYWORD

nonn

AUTHOR

J. Lowell, May 10 2014

EXTENSIONS

More terms from Michel Marcus, May 11 2014

STATUS

approved

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Last modified October 21 16:25 EDT 2019. Contains 328302 sequences. (Running on oeis4.)