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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

%I

%S 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,

%T 64,65,74,75,76,77,78,79,80,87,88,109,110,111,112,113,114,115,116,137,

%U 138,158,159,160,161,162,163,164,165,166,167,178,179,214,215,216,217,218

%N 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.

%e 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

%p 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

%Y Cf. A074138.

%K nonn

%O 1,2

%A _Amarnath Murthy_, Aug 28 2002

%E More terms from Fung Cheok Yin (cheokyin_restart(AT)yahoo.com.hk), Sep 30 2006

%E More terms from _R. J. Mathar_, Mar 30 2007

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Last modified August 17 19:38 EDT 2022. Contains 356189 sequences. (Running on oeis4.)