A244733 Semiprimes sp such that sp plus its digit sum is a perfect square.

38, 86, 161, 614, 662, 998, 1145, 1355, 1829, 2189, 2483, 4607, 5027, 5315, 6377, 7199, 8258, 11435, 13214, 15611, 17933, 19574, 20153, 21305, 21878, 24014, 26867, 30599, 32738, 34199, 36077, 38387, 38777, 40778, 42422, 46211, 51509, 52874, 56618, 58541, 59987

Offset

1,1

Links

K. D. Bajpai, Table of n, a(n) for n = 1..1150

Example

86 is in the sequence because 86 = 2* 43, which is semiprime. Also, 86 + (8 + 6) = 100 = 10^2.
614 is in the sequence because 614 = 2* 307, which is semiprime. Also, 614 + (6 + 1 + 4) = 625 = 25^2.

Mathematica

Select[Range[50000], PrimeOmega[#] == 2 && IntegerQ[Sqrt[# + Apply[Plus, IntegerDigits[#]]]] &]

Crossrefs

Cf. A007953, A028839, A048519, A107288, A244863.

Sequence in context: A044024 A133529 A211498 * A044176 A044557 A014716

Adjacent sequences: A244730 A244731 A244732 * A244734 A244735 A244736

Keyword

nonn,base

Author

K. D. Bajpai, Jul 12 2014

Status

approved