This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A213348 #26 Nov 21 2019 00:09:32 %S A213348 1,14,112,8,672,144,3360,1440,45,14784,10560,990,59136,63360,11880, %T A213348 220,219648,329472,102960,5720,768768,1537536,720720,80080,1001, %U A213348 2562560,6589440,4324320,800800,30030,8200192,26357760,23063040 %N A213348 6-quantum transitions in systems of N >= 6 spin 1/2 particles, in columns by combination indices. %C A213348 For a general discussion, please see A213343. %C A213348 This a(n) is for sextuple-quantum transitions (q = 6). %C A213348 It lists the flattened triangle T(6;N,k) with rows N = 6,7,... and columns k = 0..floor((N-6)/2). %D A213348 See A213343 %H A213348 Stanislav Sykora, <a href="/A213348/b213348.txt">Table of n, a(n) for n = 6..2309</a> %H A213348 Stanislav Sykora, <a href="/A213348/a213348.txt">T(6;N,k) with rows N = 6..100 and columns k = 0..floor((N-6)/2)</a> %H A213348 Stanislav Sýkora, <a href="http://www.ebyte.it/stan/blog12to14.html#14Dec31">Magnetic Resonance on OEIS</a>, Stan's NMR Blog (Dec 31, 2014), Retrieved Nov 12, 2019. %F A213348 Set q = 6 in: T(q;N,k) = 2^(N-q-2*k)*binomial(N,k)*binomial(N-k,q+k). %e A213348 Starting rows of the triangle: %e A213348 N | k = 0, 1, ..., floor((N-6)/2) %e A213348 6 | 1 %e A213348 7 | 14 %e A213348 8 | 112 8 %e A213348 9 | 672 144 %e A213348 10 | 3360 1440 45 %t A213348 With[{q = 6}, Table[2^(n - q - 2 k)*Binomial[n, k] Binomial[n - k, q + k], {n, q, q + 10}, {k, 0, Floor[(n - q)/2]}]] // Flatten (* _Michael De Vlieger_, Nov 20 2019 *) %o A213348 (PARI) See A213343; set thisq = 6 %Y A213348 Cf. A051288 (q=0), A213343 to A213347 (q=1 to 5), A213349 to A213352 (q=7 to 10). %Y A213348 Cf. A002409 (first column, with offset 6), A004312 (row sums). %K A213348 nonn,tabf %O A213348 6,2 %A A213348 _Stanislav Sykora_, Jun 13 2012