A356396 Nonnegative numbers k such that the negaFibonacci representation of -k (A215023(k)) is palindromic.
0, 2, 7, 20, 26, 44, 54, 73, 112, 143, 159, 196, 212, 264, 290, 350, 376, 426, 492, 518, 568, 675, 756, 798, 905, 986, 1028, 1125, 1167, 1280, 1361, 1403, 1500, 1542, 1683, 1751, 1908, 1976, 2107, 2290, 2358, 2515, 2583, 2714, 2887, 2955, 3086, 3275, 3343
Offset: 1
Examples
The first terms are: n a(n) A215023(a(n)) -- ---- ------------- 1 0 0 2 2 1001 3 7 100001 4 20 10000001 5 26 10100101 6 44 1001001001 7 54 1000000001 8 73 1010000101 9 112 100100001001 10 143 100000000001
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Programs
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PARI
is(n) = { my (v=0, neg=0, pos=0, f); n=-n; for (e=0, oo, f=fibonacci(-1-e); if (f<0, neg+=f, pos+=f); if (neg <=n && n <= pos, while (n, if (f<0, neg-=f, pos-=f); if (neg > n || n > pos, v+=2^e; n-=f); f=fibonacci(-1-e--)); my (b=binary(v)); return (b==Vecrev(b)))) }
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