Generalising Unique Sums beyond A025582 and A051912
Wouter Meeussen
w.meeussen.vdmcc at vandemoortele.be
Tue Jan 11 19:21:41 CET 2000
Generalising Unique Sums beyond A025582 and A051912
Origin:
in a net (lattice?) with j neighbourhoods, the 'energy' of a cell
is the sum of the interaction-energies with its neighbours.
Say that there are m types of neighbours (20 amino-acids, ..).
Choose a basis such that there is no accidental energy equality for
any combination of j neighbours.
seq_j = {0 , 1 , j+1 , j^2+j+1 , ... == { seq[j,0],seq[j,1],seq[j,2],... }
seq[j,m] is least integer such that the sums of all combinations of j terms taken from
seq[j,0] upto seq[j,m-1] incl. are unique, giving Pochhammer[m , j]/j! different terms.
seq_2={0,1, 3, 7, 12,20,30,44,65,80,96,122,147,181,203,251,289,360,400,474,564,592,661,774,
821,915,969,1015,1158,1311,1394,1522} = A025582
seq_3={0,1, 4, 13, 32,71,124,218,375,572,744,1208,1556,2441,3097,4047,5297,6703,7838,
10986,12331,15464,19143,24545,28973,34405,37768,45863,50876} = A051912
seq_4={0,1, 5, 21, 55,153,368,856,1424,2603,4967,8194}
seq_5={0,1, 6, 31, 108,366,926,2286,5733 }
looking vertically (columnwise):
Table[seqn[j,i],{j,1,10},{i,5}]
{0, 1, 2, 3, 4, ...
{0, 1, 3, 7, 12},
{0, 1, 4, 13, 32},
{0, 1, 5, 21, 55},
{0, 1, 6, 31,108},
{0, 1, 7, 43, 154},
{0, 1, 8, 57, 256},
{0, 1, 9, 73, 333},
{0, 1,10, 91, 500},
{0, 1,11, 111, 616,
...
{3, 7, 13, 21, 31, 43, 57, 73, 91, 111, 133, 157, 183, 211, 241, 273} is known:
ID Number: A002061 (Formerly M2638 and N1049)
Sequence: 1,1,3,7,13,21,31,43,57,73,91,111,133,157,183,211,241,273,
307,343,381,421,463,507,553,601,651,703,757,813,871,931,993,
1057,1123,1191,1261
Name: Central polygonal numbers: n^2 - n + 1.
References Archimedeans Problems Drive, Eureka, 22 (1959), 15.
L. Hogben, Choice and Chance by Cardpack and Chessboard. Vol. 1,
Chanticleer Press, NY, 1950, p. 22.
R. Honsberger, Ingenuity in Math., Random House, 1970, p. 87.
Keywords: nonn,easy,nice
Offset: 0
Author(s): njas
the next column isn't:
{4,12,32,55,108,154,256,333,500,616,864,1027,1372,1590,2048,2329,...}
I am sorry, but the terms
12,32,55,108,154,256,333,500,616
do not match anything in the table
What? No GF? can sums be hard?
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