A120245 a(1) = 1. a(m(m+1)/2 + k) = a(m) + a(k), 1 <= k <= m+1, m >= 1.
1, 2, 3, 3, 4, 5, 4, 5, 6, 6, 4, 5, 6, 6, 7, 5, 6, 7, 7, 8, 9, 6, 7, 8, 8, 9, 10, 9, 5, 6, 7, 7, 8, 9, 8, 9, 6, 7, 8, 8, 9, 10, 9, 10, 11, 7, 8, 9, 9, 10, 11, 10, 11, 12, 12, 7, 8, 9, 9, 10, 11, 10, 11, 12, 12, 10, 5, 6, 7, 7, 8, 9, 8, 9, 10, 10, 8, 9, 6, 7, 8, 8, 9, 10, 9, 10, 11, 11, 9, 10, 11, 7, 8
Offset: 1
Links
- Kevin Ryde, Table of n, a(n) for n = 1..10011
- Michael De Vlieger, Annotated fan-style heat map of a(n), n = 1..3321, showing n = k(k+1)/2..(k+1)(k+2)/2-1 in semicircular row k, where purples and blues indicate smallest values and reds and magentas largest values in the sequence.
- Kevin Ryde, PARI/GP Code
Programs
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Mathematica
nn = 12; a[1] = 1; Do[Set[j, a[m] + a[k]]; Set[a[m (m + 1)/2 + k], j], {m, nn}, {k, m + 1}]; Array[a, # (# + 1)/2] &[nn + 1] (* Michael De Vlieger, Aug 23 2022 *) -
PARI
\\ See links.
Extensions
Extended by Ray Chandler, Jun 19 2006