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A216237 Happy palindromic numbers. 1
1, 7, 44, 262, 313, 383, 404, 464, 565, 656, 818, 888, 989, 1221, 1771, 1881, 2112, 3553, 4004, 4554, 4774, 5335, 5445, 5555, 7117, 7447, 7887, 8118, 8778, 11311, 11811, 12021, 12321, 12921, 14641, 15451, 15951, 17071, 17371, 18081, 18381, 20602, 21012 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

That is, happy numbers (A007770) that are palindromic (A002113).

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

FORMULA

A103369(a(n)) * A136522(a(n)) = 1. - Reinhard Zumkeller, Mar 15 2013

MATHEMATICA

palQ[n_] := Block[{d=IntegerDigits@n}, d == Reverse@d]; happyQ[n_] := Block[{w = n}, While[w > 6, w = Total[IntegerDigits[w]^2]]; w == 1]; Select[Range[21012], palQ[#] && happyQ[#] &] (* Giovanni Resta, Mar 14 2013 *)

PROG

(Haskell)

a216237 n = a216237_list !! (n-1)

a216237_list = filter ((== 1) . a136522) a007770_list

-- Reinhard Zumkeller, Mar 15 2013

CROSSREFS

Cf. A002113, A007770.

Sequence in context: A203210 A323923 A026116 * A291388 A037531 A178719

Adjacent sequences:  A216234 A216235 A216236 * A216238 A216239 A216240

KEYWORD

nonn,base,easy

AUTHOR

Jayanta Basu, Mar 14 2013

STATUS

approved

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Last modified October 20 08:28 EDT 2021. Contains 348099 sequences. (Running on oeis4.)