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A074137
a(1) = 1; then append numbers greater than the previous term so that the n-th term a(n) divides the sum of next a(n) terms.
3
1, 2, 3, 5, 6, 7, 8, 9, 10, 11, 15, 16, 22, 23, 30, 31, 40, 41, 51, 52, 53, 54, 55, 56, 57, 64, 65, 74, 75, 76, 77, 78, 79, 80, 87, 88, 109, 110, 111, 112, 113, 114, 115, 116, 137, 138, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 178, 179, 214, 215, 216, 217, 218
OFFSET
1,2
EXAMPLE
a(11)=15, the sum of next 14 terms: 16+22+...+57=581. 581+58=639=15*42+9, 581+59=15*42+10, ..., 581+64 = 15*43. So a(11+15)=a(26)=64
MAPLE
A074137 := proc(nmax) local a, ipiv, apiv, incsum, nexta ; a := [1, 2, 3] ; ipiv := 2 ; while nops(a) < nmax do apiv := op(ipiv, a) ; while nops(a) < ipiv+apiv-1 do a := [op(a), op(-1, a)+1] ; od ; incsum := add(op(i, a), i=ipiv+1..nops(a)) ; nexta := apiv - ( incsum mod apiv ) ; while nexta <= op(-1, a) do nexta := nexta+apiv ; od ; a := [op(a), nexta] ; ipiv := ipiv+1 ; od ; a ; end ; A074137(180) ; # R. J. Mathar, Mar 30 2007
CROSSREFS
Cf. A074138.
Sequence in context: A261406 A264387 A282843 * A206027 A039222 A340745
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Aug 28 2002
EXTENSIONS
More terms from Fung Cheok Yin (cheokyin_restart(AT)yahoo.com.hk), Sep 30 2006
More terms from R. J. Mathar, Mar 30 2007
STATUS
approved