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A086540
Numbers n such that n and n+1 both are members of A074997; i.e., on the one hand n-1 and n+1 have the same prime signature, on the other hand n and n+2 have the same prime signature.
1
18, 55, 248, 340, 348, 722, 850, 949, 1061, 1148, 1204, 1205, 1241, 1277, 1314, 1315, 1667, 1672, 2148, 2716, 2948, 2949, 3258, 3581, 3650, 3651, 4044, 4265, 4627, 4842, 5092, 5093, 5451, 5741, 5765, 6244, 6355, 6356, 6565, 6640, 6851, 6963, 7362, 7404
OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
PROG
(PARI) isok1(n) = vecsort(factor(n-1)[, 2]) == vecsort(factor(n+1)[, 2]);
isok(n) = isok1(n) && isok1(n+1); \\ Michel Marcus, Jul 28 2015
CROSSREFS
Cf. A074997.
Sequence in context: A088593 A033571 A041632 * A041634 A044975 A251252
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Aug 22 2003
EXTENSIONS
More terms from David Wasserman, Mar 21 2005
STATUS
approved