A344280 Numbers that are both 10-gonal numbers (A001107) and 10-gonal pyramidal numbers (A007585).

0, 1, 175, 368050005576

Offset

1,3

Comments

Terms correspond to integral points on an elliptic curve, which allows all of them to be found efficiently. - Max Alekseyev, Jul 16 2026

Links

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

Numberphile, Cannon Ball Numbers.

Prog

(PARI) for(k=0, 1e4, if(ispolygonal(m=k*(k+1)*(8*k-5)/6, 10), print1(m", ")))

Crossrefs

Intersection of A001107 and A007585.

Cf. A027568, A344376, A344377.

Sequence in context: A383757 A212946 A172685 * A266058 A261678 A136603

Adjacent sequences: A344277 A344278 A344279 * A344281 A344282 A344283

Keyword

nonn,fini,full,changed

Author

Seiichi Manyama, May 17 2021

Status

approved