

A216853


18k^212k7 interleaved with 18k^2+6k+5 for k>=0.


0



7, 5, 1, 29, 41, 89, 119, 185, 233, 317, 383, 485, 569, 689, 791, 929, 1049, 1205, 1343, 1517, 1673, 1865, 2039, 2249, 2441, 2669, 2879, 3125, 3353, 3617, 3863, 4145, 4409, 4709, 4991, 5309, 5609, 5945, 6263, 6617, 6953, 7325, 7679, 8069, 8441, 8849
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OFFSET

0,1


COMMENTS

The sequence (the third in the family) is present as a family of single interleaved sequence of which there are many which are separated or factored out to give individual sequences. The larger sequence produces two smaller interleaved sequences where one of them has the formulas above and the other interleaved sequence has the formulas (18n^224n1) and (18n^26n+5). The latter interleaved sequence is A214493. There are three sequences in this family.


LINKS



FORMULA

G.f.: (719*x+11*x^217*x^3)/((1+x)*(1x)^3).  Bruno Berselli, Oct 05 2012


MATHEMATICA

Flatten[Table[{18 n^2  12 n  7, 18 n^2 + 6 n + 5}, {n, 0, 22}]] (* Bruno Berselli, Oct 05 2012 *)


PROG

(Magma) &cat[[18*k^212*k7, 18*k^2+6*k+5]: k in [0..22]]; // Bruno Berselli, Oct 05 2012
(PARI) vector(46, n, k=(n1)\2; if(n%2, 18*k^212*k7, 18*k^2+6*k+5)) \\ Bruno Berselli, Oct 05 2012


CROSSREFS



KEYWORD

sign,easy


AUTHOR



EXTENSIONS



STATUS

approved



