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URL: https://oeis.org/A225892

⇱ A225892 - OEIS

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A225892
Numbers of the form p^2 * (p^2 + 1) where p is in A225856.
1
20, 90, 650, 14762, 28730, 83810, 130682, 280370, 708122, 924482, 1875530, 4881890, 7893290, 12120842, 13849562, 20155610, 25416722, 28403570, 38956322, 47465210, 62750162, 88538690, 104070602, 112561490, 141170042, 163060130, 260160770, 294517082, 352294130
OFFSET
1,1
LINKS
FORMULA
a(n) = A071253(A225856(n)). - Amiram Eldar, Feb 23 2021
EXAMPLE
a(2) = 3^2(3^2+1) = 3^4+3^2 = 90.
a(5) = 13^2(13^2+1) = 13^4+13^2 = 28730.
MATHEMATICA
p = Select[Prime[Range[60]], SquareFreeQ[#^2+1]&]; p^2 * (p^2+1)
#^2 (#^2+1)&/@Select[Prime[Range[50]], SquareFreeQ[#^2+1]&] (* Harvey P. Dale, Jun 17 2022 *)
CROSSREFS
Cf. A071253, A225856 (primes p such that p^2+1 is squarefree).
Sequence in context: A386745 A225882 A281768 * A366933 A211140 A200431
KEYWORD
nonn
AUTHOR
Rafael Parra Machio, May 20 2013
STATUS
approved