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A209257 A musically inspired Titius-Bode-like sequence based on the geometric division of 4- and 5-dimensional space: Z_(n+1) = 3 * (C(n-1, 0) + C(n-1, 1) + C(n-1, 2) + C(n-1, 3) + C(n-1, 4) + C(n-1, 5)*A059620(n+6)) + 4.

%I A209257 #34 Feb 18 2025 03:58:14
%S A209257 4,7,10,16,28,52,97,193,301,493,1150,1162,3076,2386,3283,10423,5827,
%T A209257 20659,9646,37852,15112,18592,83692,27331,133660,38857,45832,251050,
%U A209257 62566,367318,83527,523315,109375,124351,852826,158872,1152508,200140,223561,1754809
%N A209257 A musically inspired Titius-Bode-like sequence based on the geometric division of 4- and 5-dimensional space: Z_(n+1) = 3 * (C(n-1, 0) + C(n-1, 1) + C(n-1, 2) + C(n-1, 3) + C(n-1, 4) + C(n-1, 5)*A059620(n+6)) + 4.
%C A209257 The classical Titius-Bode version of this sequence is given in A003461.
%C A209257 C(n, 0) + C(n, 1) + C(n, 2) + C(n, 3) + C(n, 4) = A000127(n) = A059173(n+1)/2.
%C A209257 C(n, 0) + C(n, 1) + C(n, 2) + C(n, 3) + C(n, 4) + C(n, 5) = A006261(n) = A059174(n+1)/2.
%C A209257 Where planetary and dwarf-planetary distances from the Sun at semi-major axis are expressed in astronomical units/10, then compare the following (noting that the running correlation coefficient, r, trends upwards as the population size increases):
%C A209257 n = 0, Mercury @ semi-major =   3.8710 vs.   4.0 -->  96.78%.
%C A209257 n = 1, Venus   @ semi-major =   7.2333 vs.   7.0 --> 103.33%.
%C A209257 n = 2, Earth   @ semi-major =  10.0000 vs.  10.0 --> 100.00%,  r = 0.998430.
%C A209257 n = 3, Mars    @ semi-major =  15.2368 vs.  16.0 -->  95.23%,  r = 0.998356.
%C A209257 n = 4, Ceres   @ semi-major =  27.654  vs.  28.0 -->  98.76%,  r = 0.999412.
%C A209257 n = 5, Jupiter @ semi-major =  52.0427 vs.  52.0 --> 100.08%,  r = 0.999809.
%C A209257 n = 6, Saturn  @ semi-major =  95.8202 vs.  97.0 -->  98.78%,  r = 0.999937.
%C A209257 n = 7, Uranus  @ semi-major = 192.2941 vs. 193.0 -->  99.63%,  r = 0.999981.
%C A209257 n = 8, Neptune @ semi-major = 301.0366 vs. 301.0 --> 100.01%,  r = 0.999990.
%C A209257 The correspondence between this sequence and planetary distances breaks down subsequent to Neptune unless one adopts the conceit of considering the outer four dwarf planets -- Pluto, Haumea, MakeMake and Eris -- as one unit occupying one "planetary band" (note that Eris @ perihelion is inside the Kuiper Belt). Then:
%C A209257 n = 9, Pluto/Haumea/MakeMake/Eris @ semi-major ~ 490.492 average vs. 493.0 --> 99.49%, r = 0.999994.
%C A209257 Empirical source: Wikipedia planet pages as of Jan 14 2013.
%C A209257 This sequence originated as part of an attempt to compare and contrast the "good" numerology of Johann Balmer to the "bad" numerology of Titius-Bode. Coincidentally, (Totient(C(31, 0) + C(31, 1) + C(31, 2) + C(31, 3) + C(31, 4)))/10^11 equals 3.6456*10^-7, in meters, the Balmer constant as given by Johann Balmer in 1885.
%H A209257 G. C. Greubel, <a href="/A209257/b209257.txt">Table of n, a(n) for n = 0..1000</a>
%H A209257 J. Baez, <a href="http://math.ucr.edu/home/baez/week234.html">This Week's Finds in Mathematical Physics (Week 234)</a>
%H A209257 H. Chang, <a href="http://www.janss.kr/Upload/files/JASS/27_1_01.pdf">Titius-Bode’s Relation and Distribution of Exoplanets </a>
%H A209257 D. M. F. Chapman, <a href="http://astronomia.udea.edu.co/sitios/astronomia-2.0/pages/metcomp.rs/files/Tareas/Tarea5/71755174/2001JRASC..95..189C.pdf">The Titius-Bode Rule, Part 2: Science or Numerology?</a>
%H A209257 Chemteam, <a href="http://www.chemteam.info/Electrons/Balmer-Formula.html">The Balmer Formula</a>
%H A209257 A. L. Kholodenko, <a href="http://arxiv.org/abs/1003.5696">Role of general relativity and quantum mechanics in dynamics of Solar System</a>
%H A209257 Wikipedia, <a href="http://en.wikipedia.org/wiki/Dwarf_planet">Dwarf planet</a>
%H A209257 Wikipedia, <a href="http://en.wikipedia.org/wiki/Planet">Planet</a>
%H A209257 Wikipedia, <a href="http://en.wikipedia.org/wiki/Titius-Bode_law">Titius-Bode law</a>
%F A209257 Z_(n+1) = 3 * (C(n-1, 0) + C(n-1, 1) + C(n-1, 2) + C(n-1, 3) + C(n-1, 4) + C(n-1, 5)*(floor((5*(n+6)+7)/12) - floor((5*(n+6)+2)/12))) + 4.
%e A209257 Z_1 = 3*((1 - 1 +  1 -  1 +  1) + (-1 * 1)) + 4 =   4,
%e A209257 Z_2 = 3*((1 + 0 +  0 +  0 +  0) +  (0 * 0)) + 4 =   7,
%e A209257 Z_3 = 3*((1 + 1 +  0 +  0 +  0) +  (0 * 0)) + 4 =  10,
%e A209257 Z_4 = 3*((1 + 2 +  1 +  0 +  0) +  (0 * 1)) + 4 =  16,
%e A209257 Z_5 = 3*((1 + 3 +  3 +  1 +  0) +  (0 * 0)) + 4 =  28,
%e A209257 Z_6 = 3*((1 + 4 +  6 +  4 +  1) +  (0 * 1)) + 4 =  52,
%e A209257 Z_7 = 3*((1 + 5 + 10 + 10 +  5) +  (1 * 0)) + 4 =  97,
%e A209257 Z_8 = 3*((1 + 6 + 15 + 20 + 15) +  (6 * 1)) + 4 = 193,
%e A209257 Z_9 = 3*((1 + 7 + 21 + 35 + 35) + (21 * 0)) + 4 = 301.
%t A209257 Z[n_]:= 3*(Binomial[n - 1, 0] + Binomial[n - 1, 1] + Binomial[n - 1, 2] + Binomial[n - 1, 3] + Binomial[n - 1, 4] + Binomial[n - 1, 5]*(Floor[(5 (n + 6) + 7)/12] - Floor[(5 (n + 6) + 2)/12])) + 4; Table[Z[n], {n, 0, 50}] (* _G. C. Greubel_, Jan 07 2018 *)
%o A209257 (PARI) {z(n) = 3*(binomial(n-1,0) + binomial(n-1,1) + binomial(n-1,2) + binomial(n-1,3) + binomial(n-1,4) + binomial(n-1,5)*(floor((5*(n+6) + 7)/12) - floor((5*(n+6)+2)/12))) + 4};
%o A209257 for(n=0,30, print1(z(n), ", ")) \\ _G. C. Greubel_, Jan 07 2018
%o A209257 (Magma) [3*(Binomial(n-1,0) + Binomial(n-1,1) + Binomial(n-1,2) + Binomial(n-1,3) + Binomial(n-1,4) + Binomial(n-1,5)*(Floor((5*(n+6) + 7)/12) - Floor((5*(n+6)+2)/12))) + 4: n in [0..30]]; // _G. C. Greubel_, Jan 07 2018
%Y A209257 Cf. A003461, A059620, A000127, A059173, A006261, A059174.
%K A209257 nonn,easy
%O A209257 0,1
%A A209257 _Raphie Frank_, Jan 14 2013
%E A209257 a(18) corrected by _G. C. Greubel_, Jan 07 2018