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Revision History for A249722 (Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

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Numbers n such that there is a multiple of 4 on row n of Pascal's triangle with property that all multiples of 9 on the same row (if they exist) are larger than it.
(history; published version)
#13 by N. J. A. Sloane at Wed Nov 05 11:24:03 EST 2014
STATUS

editing

approved

#12 by N. J. A. Sloane at Wed Nov 05 11:23:44 EST 2014
NAME

Numbers n such that there is such a multiple of 4 on row n of Pascal's triangle with property that all multiples of 9 on the same row (if they exist) are larger than it.

STATUS

proposed

editing

Discussion
Wed Nov 05
11:24
N. J. A. Sloane: Improved grammar of definition slightly
#11 by Antti Karttunen at Wed Nov 05 08:11:42 EST 2014
STATUS

editing

proposed

#10 by Antti Karttunen at Wed Nov 05 07:35:56 EST 2014
COMMENTS

Natural numbers A000027 All n such that on row n of A034931 (Pascal's triangle reduced modulo 4) there is at least one zero and the distance from the edge to the nearest zero is a disjoint union shorter than the distance from the edge to the nearest zero on row n of A095143 (Pascal's triangle reduced modulo 9), the latter distance taken to be infinite if there are no zeros on that row in the sequences A048278, A249722, A249723, A249726latter triangle.

EXAMPLE

Row 4 of Pascal's triangle (A007318) is {1,4,6,4,1}. The least multiple of 4 occurs as C(4,1) = 4, and there are no multiples of 9 present, thus 4 is included among the terms.

Row 12 of Pascal's triangle is {1,12,66,220,495,792,924,792,495,220,66,12,1}. The least multiple of 4 occurs as C(12,1) = 12, which is less than the least multiple of 9 present at C(12,4) = 495 = 9*55, thus 12 is included among the terms.

CROSSREFS

Cf. Natural numbers (A000027) is a disjoint union of the sequences A048278, A249722, A249723, and A249726, A048645, A051382.

Cf. A007318, A034931, A095143, A048645, A051382.

#9 by Antti Karttunen at Wed Nov 05 07:30:52 EST 2014
EXAMPLE

Row 4 of Pascal's triangle is {1,4,6,4,1}. The first least multiple of 4 occurs as C(4,1) = 4, and there are no multiples of 9 present, thus 4 is included among the terms.

Row 6 12 of Pascal's triangle is {1,6,15,20,15,6,12,66,220,495,792,924,792,495,220,66,12,1}. The first least multiple of 4 occurs as C(6,312,1) = 20, and there are no multiples 12, which is less than the least multiple of 9 present, at C(12,4) = 495 = 9*55, thus 6 12 is included among the terms.

Row 12 of Pascal's triangle is {1,12,66,220,495,792,924,792,495,220,66,12,1}. The first multiple of 4 is C(12,1) = 12, which is less than the first multiple of 9 at C(12,4) = 495 = 9*55, thus 12 is included among the terms.

#8 by Antti Karttunen at Wed Nov 05 07:29:09 EST 2014
EXAMPLE

Row 4 of Pascal's triangle is {1,4,6,4,1}. The first multiple of 4 occurs as C(4,1) = 4, and there are no multiples of 9 present, thus 4 is included among the terms.

Row 6 of Pascal's triangle is {1,6,15,20,15,6,1}. The first multiple of 4 occurs as C(6,3) = 20, and there are no multiples of 9 present, thus 6 is included among the terms.

Row 12 of Pascal's triangle is {1,12,66,220,495,792,924,792,495,220,66,12,1}. The first multiple of 4 is C(12,1) = 12, which is less than the first multiple of 9 at C(12,4) = 495 = 9*55, thus 12 is included among the terms.

#7 by Antti Karttunen at Wed Nov 05 07:18:56 EST 2014
CROSSREFS
#6 by Antti Karttunen at Wed Nov 05 07:18:14 EST 2014
NAME

Numbers n such that there is such a term divisible by multiple of 4 on row n of Pascal's triangle and there are no lesser or equal terms divisible by that all multiples of 9 on the same row (if they exist) are larger than it.

#5 by Antti Karttunen at Tue Nov 04 16:09:05 EST 2014
CROSSREFS

A subsequence of A249724.

#4 by Antti Karttunen at Tue Nov 04 13:44:22 EST 2014
COMMENTS

Natural numbers A000027 is a disjoint union of the sequences A048278, A249722, A249723, A249726.