A206626 - OEIS

A206626

Primes p such that p + previousprime(p) is a squarefree number.

3, 17, 23, 41, 71, 97, 107, 113, 131, 167, 197, 211, 223, 233, 311, 383, 397, 401, 457, 467, 479, 487, 491, 503, 521, 617, 647, 673, 691, 709, 727, 743, 761, 773, 809, 863, 881, 887, 907, 919, 937, 941, 971, 991, 1009, 1013, 1097, 1117, 1171, 1213, 1249, 1283

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..52.

FORMULA

a(n) = A206329(n) - A206462 (n).

EXAMPLE

3+2 = 5 = A206462(1), 17+13 = 30 = A206462(2).

MATHEMATICA

Select[Prime[Range[250]], SquareFreeQ[#+NextPrime[#, -1]]&] (* Harvey P. Dale, Sep 21 2023 *)

CROSSREFS