A343192 Happy Honaker primes.
263, 1039, 1933, 2221, 3067, 3137, 5741, 6343, 6353, 6971, 7481, 8821, 9103, 10247, 11251, 12347, 13037, 13339, 13457, 13933, 14437, 16451, 17317, 18041, 21617, 26309, 26339, 30091, 30293, 31177, 32009, 34471, 35227, 36307, 36433, 37117, 41131, 41333, 41801, 43781
Offset: 1
Examples
263 is a Honaker prime: the number of primes up to 263 is 56 and 2 + 6 + 3 = 11 = 5 + 6. 263 is also a Happy number: iterating the sum of squares of digits terminates in 1, i.e., 263 -> 4 + 36 + 9 = 49 -> 16 + 81 = 97 -> 81 + 49 = 130 -> 1 + 9 + 0 = 10 -> 1 + 0 = 1. Thus 263 is a Happy Honaker prime.
Links
- K. D. Bajpai, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
Select[Prime[Range[20000]], FixedPoint[Total[IntegerDigits[#]^2] &, #, 10] == 1 && Plus @@ IntegerDigits@# == Plus @@ IntegerDigits@PrimePi@# &]
Comments