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A307174 Numbers that are both triangular and icosahedral. 1
0, 1, 1128, 87153 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

The list is probably finite, like the list of triangular and tetrahedral numbers (A027568).

It would appear that the similar sequence of pentagonal-dodecahedral numbers contains only the trivial cases of 0 and 1.

Intersection of A000217 and A006564. - A.H.M. Smeets, Aug 19 2019

LINKS

Table of n, a(n) for n=1..4.

MATHEMATICA

Intersection[Accumulate[Range[0, 199]], Table[n (5n^2 - 5n + 2)/2, {n, 0, 99}]] (* Alonso del Arte, Jul 10 2019 *)

PROG

(PARI) lista(nn) = for (n=0, nn, if (ispolygonal(k=n*(5*n^2 - 5*n + 2)/2, 3), print1(k, ", "))); \\ Michel Marcus, Jul 10 2019

CROSSREFS

Cf. A000217, A006564, A027568, A309009.

Sequence in context: A252299 A203063 A237294 * A278732 A278434 A198469

Adjacent sequences:  A307171 A307172 A307173 * A307175 A307176 A307177

KEYWORD

nonn,fini,more,bref

AUTHOR

William C. Laursen, Jul 09 2019

STATUS

approved

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Last modified September 25 04:28 EDT 2022. Contains 356953 sequences. (Running on oeis4.)