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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 (list; graph; refs; listen; history; text; internal format)
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

Adjacent sequences: A086537 A086538 A086539 * A086541 A086542 A086543

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Aug 22 2003

EXTENSIONS

More terms from David Wasserman, Mar 21 2005

STATUS

approved

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Last modified February 1 08:11 EST 2023. Contains 359982 sequences. (Running on oeis4.)