A154716 Products of three consecutive happy primes A035497.

1729, 5681, 13547, 56327, 237553, 789289, 1089019, 1560553, 2530217, 4480109, 7703209, 12131401, 18417101, 24119467, 30355679, 38022301, 46039783, 53272619, 57627329, 62188859, 79075651, 112140029, 169169677, 226833263, 271152373, 300157327, 325898231

Offset

1,1

Comments

Note that a(1) = 1729 is the Hardy-Ramanujan number (see taxicab numbers in A001235, A011541).

Links

Table of n, a(n) for n=1..27.

Mathematica

happyQ[n_, b_] := NestWhile[Total[IntegerDigits[#, b]^2] &, n, UnsameQ, All] == 1; Times @@@ Partition[Select[Prime[Range[150]], happyQ[#, 10] &], 3, 1] (* Amiram Eldar, Jan 17 2025 *)

Crossrefs

Cf. A001235, A011541, A035497, A154717, A154728, A154729.

Sequence in context: A350270 A130859 A245671 * A375322 A154728 A286217

Adjacent sequences: A154713 A154714 A154715 * A154717 A154718 A154719

Keyword

easy,nonn,base

Author

Omar E. Pol, Jan 18 2009

Extensions

a(5)-a(27) from Nathaniel Johnston, Apr 30 2011

Status

approved