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A272266
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The union of squares (A000290) and 10-gonal numbers (A001107).
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2
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1, 4, 9, 10, 16, 25, 27, 36, 49, 52, 64, 81, 85, 100, 121, 126, 144, 169, 175, 196, 225, 232, 256, 289, 297, 324, 361, 370, 400, 441, 451, 484, 529, 540, 576, 625, 637, 676, 729, 742, 784, 841, 855, 900, 961, 976, 1024, 1089, 1105, 1156, 1225, 1242, 1296
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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LINKS
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FORMULA
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Conjectures:
a(n) = a(n-1)+2*a(n-3)-2*a(n-4)-a(n-6)+a(n-7) for n>7.
G.f. x*(1+3*x+5*x^2-x^3-x^5+x^6) / ((1-x)^3*(1+x+x^2)^2).
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PROG
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(PARI)
pg(m, n) = (n^2*(m-2)-n*(m-4))/2 \\ The n-th m-gonal number
pgr(m, r) = n=1; L=List(); while((t=pg(m, n))<r, listput(L, t); n++); Vec(L)
pgpgs(p, q, r) = setunion(pgr(p, r), pgr(q, r))
pgpgs(4, 10, 2000)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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