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A272266 The union of squares (A000290) and 10-gonal numbers (A001107). 2
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Colin Barker, Table of n, a(n) for n = 1..1000

FORMULA

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).

PROG

(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)

CROSSREFS

Cf. A000290, A001107, A272267.

Sequence in context: A260963 A243188 A117570 * A155566 A305231 A312832

Adjacent sequences:  A272263 A272264 A272265 * A272267 A272268 A272269

KEYWORD

nonn

AUTHOR

Colin Barker, Apr 24 2016

STATUS

approved

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Last modified September 19 04:52 EDT 2019. Contains 327187 sequences. (Running on oeis4.)