A139419 a(n) = first term of the n-th run of consecutive numbers in A136120.

1, 3, 9, 15, 22, 36, 48, 69, 87, 116, 141, 167, 194, 222, 269, 308, 368, 419, 471, 524, 578, 633, 719, 791, 896, 986, 1077, 1169, 1262, 1356, 1451, 1591, 1710, 1876, 2020, 2213, 2383, 2604, 2801, 3051, 3276, 3502, 3729, 3957, 4186, 4416, 4647, 4879, 5112

Offset

1,2

Links

Klaus Brockhaus, Table of n, a(n) for n=1..396

Example

A136120 starts 1, 3, 4, 5, 9, 10, 15, ..., so a(1) = 1, a(2) = 3, a(3) = 9.

Mathematica

f[seq_] := Module[{s = seq, n1, n2}, n++; n1 = s[[n]] + n; If[n1 <= len, n2 = Min[n - 1 + 2*s[[n]], len]; len -= n2 - n1 + 1; Drop[s, {n1, n2}], s]]; n = 0; len = 5200; First /@Split[FixedPoint[f, Range[len]], #2 - #1 == 1 &] (* Jayanta Basu, Jun 15 2013 - using the Mma program in A136120 *)

Crossrefs

Cf. A136120, A139418, A139420.

Sequence in context: A174786 A216974 A246298 * A323031 A058972 A026222

Adjacent sequences: A139416 A139417 A139418 * A139420 A139421 A139422

Keyword

nonn

Author

Klaus Brockhaus, Apr 22 2008

Status

approved