A116468 Permutation of natural numbers generated by 2-rowed array shown below.

2, 3, 1, 6, 4, 7, 5, 10, 8, 11, 9, 14, 12, 15, 13, 18, 16, 19, 17, 22, 20, 23, 21, 26, 24, 27, 25, 30, 28, 31, 29, 34, 32, 35, 33, 38, 36, 39, 37, 42, 40, 43, 41, 46, 44, 47, 45, 50, 48, 51, 49, 54, 52, 55, 53, 58, 56, 59, 57, 62, 60, 63, 61, 66, 64, 67

Offset: 1

Author

Giovanni Teofilatto, Mar 17 2006

Keywords

• easy
• nonn

Comments

2 3 6 7 10 11 14 15 ... integers congruent to 2 or 3 mod 4

1 4 5 8 9 12 13 16 ... integers congruent to 0 or 1 mod 4

References

• M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988
• Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta,UTET, CittaStudiEdizioni, Milano 1997

Links

• Index entries for linear recurrences with constant coefficients, signature (1,0,0,1,-1).

Crossrefs

Cf. A090964.

Formula

For n>2, a(n+4k) = a(n) + 4k, with k>=1.

G.f.: x*(2+x-2*x^2+5*x^3-4*x^4+2*x^5)/(1-x-x^4+x^5). - Philippe Deléham, Dec 02 2016

Extensions

Terms corrected by R. J. Mathar, Oct 25 2011