A145377 a(n) = A002324(n) mod 2.

1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

J. S. Rutherford, Generating functions for the cage isomers of the C_{20n} icosahedral fullerenes, J. Mathematical Chem., 14 (1993), 385-390. See Eq. (3).

J. S. Rutherford, The enumeration and symmetry-significant properties of derivative lattices, Act. Cryst. A48 (1992), 500-508. [See Sect. (7), p. 505.]

Index entries for characteristic functions

Formula

a(n) = A195198(n) for n >= 1.

a(n) = Sum_{ m: m^2|n } A154272(n/m^2). - Andrey Zabolotskiy, May 07 2018

Mathematica

Array[Boole@ OddQ@ If[# < 1, 0, DivisorSum[#, KroneckerSymbol[-3, #] &]] &, 105] (* Michael De Vlieger, Nov 05 2017, after Michael Somos at A002324 *)

Prog

(PARI)
A002324(n) = if( n<1, 0, sumdiv(n, d, (d%3==1) - (d%3==2)));
A145377(n) = (A002324(n)%2); \\ Antti Karttunen, Nov 06 2017

Crossrefs

Essentially same as A195198.

Cf. A002324, A154272, A003050.

Sequence in context: A266326 A185295 A214295 * A246260 A275973 A218173

Adjacent sequences: A145374 A145375 A145376 * A145378 A145379 A145380

Keyword

nonn,mult

Author

N. J. A. Sloane, Mar 12 2009

Extensions

More terms from Antti Karttunen, Nov 05 2017

Status

approved