A094589 a(1) = 1; a(n+1) = a(n) + (largest element of {a} <= n).

1, 2, 4, 6, 10, 14, 20, 26, 32, 38, 48, 58, 68, 78, 92, 106, 120, 134, 148, 162, 182, 202, 222, 242, 262, 282, 308, 334, 360, 386, 412, 438, 470, 502, 534, 566, 598, 630, 668, 706, 744, 782, 820, 858, 896, 934, 972, 1010, 1058, 1106, 1154, 1202, 1250, 1298

Offset

1,2

Comments

a(n+1) = a(n) + a(k(n)), where k(n) is the number of elements of {a} which are <= n.

Links

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Mathematica

f[n_] := Block[{t = Table[0, {n}]}, t[[1]] = 1; For[i = 1, i < n, i++, t[[i + 1]] = t[[i]] + t[[Count[t, x_ /; 0 < x <= i]]]]; t]; f@ 54 (* Michael De Vlieger, Mar 23 2015 *)

Prog

(PARI) flargest(va, n) = {vsa = vecsort(va, , 12); for (k=1, #vsa, if (vsa[k] < n, return (vsa[k])); ); }
lista(nn) = {va = [1]; print1(va[1], ", "); for (n=2, nn, newa = flargest(va, n) + va[n-1]; print1(newa, ", "); va = concat(va, newa); ); } \\ Michel Marcus, Mar 23 2015

Crossrefs

Cf. A094590, A250983 (first differences).

Sequence in context: A167379 A213476 A277085 * A071425 A115065 A333574

Adjacent sequences: A094586 A094587 A094588 * A094590 A094591 A094592

Keyword

nonn,easy

Author

Leroy Quet, Jun 07 2004

Extensions

More terms from Vladeta Jovovic, Jun 13 2004

Status

approved