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A352281 Regular triangle read by rows, T(n,k) is the least integer m such that sigma(m)/m is greater than n + (k-1)/n. 0

%I #20 Apr 26 2022 07:30:58

%S 2,12,36,180,720,2520,27720,110880,720720,10810800,122522400,

%T 1396755360,6983776800,160626866400,4497552259200,130429015516800,

%U 2021649740510400,74801040398884800,3066842656354276800,263748468446467804800,18594267025475980238400

%N Regular triangle read by rows, T(n,k) is the least integer m such that sigma(m)/m is greater than n + (k-1)/n.

%e Triangle begins:

%e 2,

%e 12, 36,

%e 180, 720, 2520,

%e 27720, 110880, 720720, 10810800,

%e 122522400, 1396755360, ...

%o (PARI) isok(i,n,k) = sigma(i)/i > n+(k-1)/n;

%o T(n,k) = my(i=1); while(!isok(i,n,k), i++); i;

%Y Cf. A000203 (sigma), A004394 (supersequence), A134716 (1st column).

%K nonn,tabl

%O 1,1

%A _Michel Marcus_, Apr 25 2022

%E More terms from _David A. Corneth_, Apr 25 2022

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Last modified September 7 18:28 EDT 2024. Contains 375749 sequences. (Running on oeis4.)