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A229291 n is in the sequence if n is prime, (n-1)/5^A112765(n-1) is a squarefree number, A112765(n-1) < 3 and every prime divisor of n-1 is in the sequence. 2
2, 3, 5, 7, 11, 23, 31, 43, 47, 67, 71, 139, 151, 211, 283, 311, 331, 431, 463, 659, 683, 691, 863, 907, 947, 967, 1051, 1151, 1291, 1303, 1319, 1367, 1427, 1511, 1699, 1867, 1979, 1987, 2011, 2111, 2131, 2311, 2351, 2531, 3011, 3023, 3083, 3323, 3851, 4099 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If n is in A226963 then n is some product of elements of this sequence.

LINKS

Table of n, a(n) for n=1..50.

MATHEMATICA

fa = FactorInteger; free[n_] := n == Product[fa[n][[i, 1]], {i,

  Length[fa[n]]}]; Os[b_, 1] = True; Os[b_, 2] = True; Os[ b_, b_] = True; Os[b_, n_] := Os[b, n] = PrimeQ[n] && free[(n - 1)/b^IntegerExponent[n - 1, b]] && IntegerExponent[n - 1, b] < 3 && Union@Table[Os[b, fa[n - 1][[i, 1]]], {i, Length[fa[n - 1]]}] == {True}; G[b_] := Select[Prime [Range[2000]], Os[b, #] &]; G[5]

CROSSREFS

Cf. A112765, A226963, A229289, A229290.

Sequence in context: A118721 A094318 A019344 * A057459 A068853 A236400

Adjacent sequences:  A229288 A229289 A229290 * A229292 A229293 A229294

KEYWORD

nonn

AUTHOR

José María Grau Ribas, Oct 06 2013

STATUS

approved

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Last modified April 22 10:22 EDT 2019. Contains 322330 sequences. (Running on oeis4.)