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A249436 Integers n such that n/2 < A249151(n) < n. 4

%I #9 Nov 04 2014 16:37:06

%S 11,29,44,55,59,69,71,111,119,125,139,188,215,223,230,233,239,251,324,

%T 335,349,351,447,458,474,479,493,494,503,509,560,593,599,647,662,701,

%U 714,719,831,835,849,895,956,959,979,991,1000,1007,1019,1034,1063,1077,1169,1224,1319,1322,1364,1376,1424,1427,1448,1507

%N Integers n such that n/2 < A249151(n) < n.

%C Integers n such that A001142(n) [product of elements on row n of Pascal's triangle] is divisible by floor[(n+1)/2]! but not by n!

%C These are the abscissas of "stray points" in the sparsely populated region between the two topmost rays visible in the scatter plot of A249151 which have slopes 1 and 1/2: A249434 (A006093) and A249424.

%H Antti Karttunen, <a href="/A249436/b249436.txt">Table of n, a(n) for n = 1..115</a>

%o (Scheme, with _Antti Karttunen_'s IntSeq-library, two alternative definitions)

%o (define A249436 (MATCHING-POS 1 0 (lambda (n) (and (> (A249151 n) (/ n 2)) (< (A249151 n) n)))))

%o (define A249436 (MATCHING-POS 1 0 (lambda (n) (and (zero? (modulo (A001142 n) (A000142 (floor->exact (/ (+ n 1) 2))))) (not (zero? (modulo (A001142 n) (A000142 n))))))))

%Y A249437 gives the corresponding values at those points.

%Y Subsequence of A249433.

%Y Cf. A000142, A001142, A249151, A006093, A249424, A249434.

%K nonn

%O 1,1

%A _Antti Karttunen_, Nov 02 2014

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Last modified April 25 07:53 EDT 2024. Contains 371964 sequences. (Running on oeis4.)