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

1,2

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

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 *)

Prog

(PARI) See links.

Crossrefs

Cf. A120244, A120246, A064064.

Sequence in context: A328801 A106500 A280315 * A120246 A361261 A120244

Adjacent sequences: A120242 A120243 A120244 * A120246 A120247 A120248

Keyword

easy,nonn

Author

Leroy Quet, Jun 12 2006

Extensions

Extended by Ray Chandler, Jun 19 2006

Status

approved