

A114033


Group the triangular numbers so that the nth 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 number of terms in the nth group.


3



1, 4, 1, 1, 5, 7, 1, 3, 17, 3, 1, 8, 11, 5, 1, 32, 1, 17, 19, 2, 19, 11, 16, 8, 19, 4, 19, 2, 29, 25, 7, 64, 9, 2, 14, 2, 37, 19, 26, 30, 12, 28, 10, 22, 1, 21, 3, 19, 49, 25, 17, 104, 53, 8, 11, 112, 19, 58, 29, 1, 61, 124, 35, 11, 9, 44, 8, 34, 46, 15, 69, 54, 73, 37, 1, 152, 77, 65
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..78.


MAPLE

A000217 := proc(n) option remember ; n*(n+1)/2 ; end: A114033 := 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..len1) mod su <> 0 do len := len+1 ; od ; if su = n then RETURN(len) ; else strt := strt+len ; fi ; od ; end: for n from 1 to 80 do printf("%d, ", A114033(n)) ; od ; # R. J. Mathar, May 10 2007


CROSSREFS

Cf. A114031, A114032.
Sequence in context: A174037 A173077 A131239 * A334426 A209417 A267990
Adjacent sequences: A114030 A114031 A114032 * A114034 A114035 A114036


KEYWORD

nonn


AUTHOR

Amarnath Murthy, Nov 13 2005


EXTENSIONS

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


STATUS

approved



