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A175651

Numbers n with property that sopf(n)+sopf(n+1) is a square.

7, 11, 22, 32, 55, 77, 111, 140, 147, 168, 175, 186, 189, 191, 242, 259, 284, 309, 363, 364, 365, 382, 391, 395, 399, 426, 455, 461, 519, 527, 538, 554, 604, 620, 639, 692, 719, 728, 745, 748, 805, 813, 861, 862, 873, 958, 964, 988, 991, 1037, 1109, 1122

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

OFFSET

1,1

COMMENTS

Or, A175649(n) is a square.

Or, positions of squares in A175649.

or, A008472(n)+A008472(n+1) is a square. Squares are in A175652.

Prime factors counted without multiplicity. - Harvey P. Dale, Jan 15 2017

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

MATHEMATICA

Position[Partition[Table[Total[FactorInteger[n][[All, 1]]], {n, 1200}], 2, 1], _?(IntegerQ[Sqrt[Total[#]]]&)]//Quiet//Flatten (* Harvey P. Dale, Jan 15 2017 *)

CROSSREFS

Cf. A008472, A175649, A175652.

Sequence in context: A081352 A190673 A345680 * A372045 A362979 A284052

Adjacent sequences: A175648 A175649 A175650 * A175652 A175653 A175654

KEYWORD

nonn

AUTHOR

Zak Seidov, Aug 03 2010

STATUS

approved

URL: https://oeis.org/A175651

⇱ A175651 - OEIS