A276705 Records in A249860.
4, 5, 7, 8, 9, 20, 55, 91, 187, 247, 391, 475, 667, 775, 1015, 1147, 1435, 1591, 1927, 2107, 2491, 2695, 3127, 3355, 3835, 4087, 4615, 4891, 5467, 5767, 6391, 6715, 7387, 7735, 8455, 8827, 9595, 9991, 10807, 11227, 12091, 12535, 13447, 13915, 14875, 15367
Offset: 1
Keywords
Programs
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Mathematica
DeleteDuplicates[Table[LCM@@(n+{-3,3}),{n,200}],GreaterEqual] (* Harvey P. Dale, Jul 30 2025 *) -
PARI
lista(nn) = {rec = 0; for (n=1, nn, an = lcm(n-3, n+3); if (an > rec, rec = an; print1(rec, ", ")););} \\ Michel Marcus, Sep 16 2016
Formula
Conjectures: (Start)
a(n) = (347+27*(-1)^n)/2 - 3*(27+(-1)^n)*n + 9*n^2 for n>6.
a(n) = a(n-1)+2*a(n-2)-2*a(n-3)-a(n-4)+a(n-5) for n>11.
G.f.: x*(4+x-6*x^2-x^3+x^4+10*x^5+35*x^6+15*x^7+27*x^8-x^9-13*x^10) / ((1-x)^3*(1+x)^2).
(End)
Comments