A058850 Palindromes that are the sum of consecutive initial odd composites.

9, 404, 1441, 7227, 20802, 73337, 2576752, 7576757, 144666441, 7584554857, 96520502569, 3584243424853, 3776886886773, 6651010101566, 9260919190629, 36028948184982063, 4095836722276385904, 8806146443446416088, 66832347055074323866, 331143864040468341133, 719190811555118091917, 906041488626884140609, 10450905369496350905401

Offset: 1

Author

Patrick De Geest, Dec 15 2000

Keywords

• nonn
• base

Comments

9 + 15 + 21 + 25 + 27 + 33 + ... + z = n. For values of z see A058849.

Links

• P. De Geest, Palindromic Sums

Crossrefs

Cf. A058848, A058849.

Programs

Mathematica

Module[{nn=35000001,c},c=Complement[Range[9,nn,2],Prime[Range[ PrimePi[ nn]]]]; Select[ Accumulate[c],IntegerDigits[#] == Reverse[ IntegerDigits[ #]]&]] (* This program generates the first 15 terms of the sequence.  To generate more, increase the value of nn. *) (* Harvey P. Dale, Sep 02 2012 *)

Extensions

a(19)-a(20) from Donovan Johnson, Sep 01 2012

a(21)-a(23) from Chai Wah Wu, Dec 06 2019