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A114032 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 n-th group sum divided by n. 3
1, 17, 7, 7, 56, 161, 30, 95, 1020, 271, 90, 802, 1452, 790, 161, 7481, 309, 5882, 8400, 980, 10260, 6850, 11152, 6081, 15903, 3589, 18221, 2023, 32166, 32805, 9926, 110565, 18518, 4114, 29188, 4225, 83902, 47859, 70552, 89332, 37916, 93302, 34920 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..43.

FORMULA

A114031(n)/n.

MAPLE

A000217 := proc(n) option remember ; n*(n+1)/2 ; end: A114031 := proc(n) local strt, su, len, i; strt := 1 ; for su from 1 to n do len := 1; while add( A000217(strt+i), i=0..len-1) mod su <> 0 do len := len+1 ; od ; if su = n then RETURN( add( A000217(strt+i), i=0..len-1) ) ; else strt := strt+len ; fi ; od ; end: A114032 := proc(n) A114031(n)/n ; end: for n from 1 to 80 do printf("%d, ", A114032(n)) ; od ; # R. J. Mathar, May 10 2007

CROSSREFS

Cf. A114032, A114033.

Sequence in context: A166211 A086763 A064545 * A107807 A075710 A048368

Adjacent sequences:  A114029 A114030 A114031 * A114033 A114034 A114035

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Nov 13 2005

EXTENSIONS

More terms from R. J. Mathar, May 10 2007

STATUS

approved

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Last modified September 19 00:22 EDT 2021. Contains 347549 sequences. (Running on oeis4.)