Group the triangular numbers so that the n-th group sum is a multiple of n. 1, (3, 6, 10, 15), (21), (28), (36, 45, 55, 66, 78), (91, 105, 120, 136, 153, 171, 190), ... Sequence contains the group sums.
A114031
Group the triangular numbers so that the n-th group sum is a multiple of n. 1, (3, 6, 10, 15), (21), (28), (36, 45, 55, 66, 78), (91, 105, 120, 136, 153, 171, 190), ... Sequence contains the group sums.
Terms
- a(0) =1a(1) =34a(2) =21a(3) =28a(4) =280a(5) =966a(6) =210a(7) =760a(8) =9180a(9) =2710a(10) =990a(11) =9624a(12) =18876a(13) =11060a(14) =2415a(15) =119696a(16) =5253a(17) =105876a(18) =159600a(19) =19600a(20) =215460a(21) =150700a(22) =256496a(23) =145944a(24) =397575a(25) =93314a(26) =491967a(27) =56644a(28) =932814a(29) =984150
External references
- oeis: A114031