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.

2, 12, 36, 180, 720, 2520, 27720, 110880, 720720, 10810800, 122522400, 1396755360, 6983776800, 160626866400, 4497552259200, 130429015516800, 2021649740510400, 74801040398884800, 3066842656354276800, 263748468446467804800, 18594267025475980238400

Offset

1,1

Links

Table of n, a(n) for n=1..21.

Example

Triangle begins:
  2,
  12, 36,
  180, 720, 2520,
  27720, 110880, 720720, 10810800,
  122522400, 1396755360, ...

Prog

(PARI) isok(i, n, k) = sigma(i)/i > n+(k-1)/n;
T(n, k) = my(i=1); while(!isok(i, n, k), i++); i;

Crossrefs

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

Sequence in context: A181825 A169630 A192385 * A361570 A294464 A366618

Adjacent sequences: A352278 A352279 A352280 * A352282 A352283 A352284

Keyword

nonn,tabl

Author

Michel Marcus, Apr 25 2022

Extensions

More terms from David A. Corneth, Apr 25 2022

Status

approved