A111363 a(n) = A108783(n) + 1.

1, 3, 7, 11, 13, 27, 31, 33, 37, 51, 53, 57, 61, 63, 127, 131, 133, 137, 151, 153, 161, 165, 167, 171, 173, 175, 177, 181, 185, 193, 195, 199, 201, 203, 215, 217, 221, 227, 229, 231, 235, 237, 241, 243, 245, 261, 263, 265, 273, 275, 279, 283, 287, 289, 291, 295

Offset: 1

Author

Paul D. Hanna and Robert G. Wilson v, Nov 08 2005

Keywords

• nonn

Comments

Positions of the 1's in A083952 but indexing that sequence starting at 1. A108783 is the preferred version.

Crossrefs

Cf. A083952. See A108783 for another version.

Programs

Mathematica

a[0] = 1; a[l_] := a[l] = Block[{k = 1, s = Sum[ a[i]*x^i, {i, 0, l - 1}]}, While[ IntegerQ[ Last[ CoefficientList[ Series[(s + k*x^l)^(1/2), {x, 0, l}], x]]] != True, k++ ]; k]; Position[ Table[a[n], {n, 0, 300}], 1] // Flatten

Formula

It appears that a(n)~4.1*n.