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.

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

Links

Table of n, a(n) for n=1..63.

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

Adjacent sequences: A074134 A074135 A074136 * A074138 A074139 A074140

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