A109952 Degrees Celsius for which Fahrenheit is a prime.

5, 15, 45, 55, 65, 75, 115, 125, 145, 155, 175, 195, 205, 215, 255, 265, 295, 315, 325, 345, 395, 405, 425, 475, 505, 525, 545, 555, 565, 595, 645, 665, 695, 705, 715, 745, 765, 775, 805, 815, 845, 855, 875, 925, 945, 975, 995, 1025, 1045, 1055, 1065, 1095

Offset: 1

Author

Zak Seidov, Jul 06 2005

Keywords

• nonn

Comments

The sequence only includes positive integer values and all terms are multiples of 5 but no terms are multiples of 10. - Harvey P. Dale, Jul 23 2025

Examples

			f = 9 c / 5 + 32; a(1) = c = 5 because f = 41 is a prime.
		

Links

• Temperature Converter.

Crossrefs

Cf. A029925, A029926.

Programs

Mathematica

f[c_]:=9 c /5 +32; A109952 = Select[Range[5, 2000, 5], PrimeQ[f[ # ]]&]
Select[Table[5 (p-32)/9,{p,Prime[Range[10,400]]}],IntegerQ] (* Harvey P. Dale, Jul 23 2025 *)