The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A272814 Palindromes such that sum of digits equals product of digits. 1
 1, 2, 3, 4, 5, 6, 7, 8, 9, 22, 12221, 13131, 21212, 31113, 1111441111, 1114114111, 1141111411, 1411111141, 4111111114, 11112421111, 11121412111, 11211411211, 12111411121, 21111411112, 111122221111, 111212212111, 111221122111, 112112211211, 112121121211 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Inspired by A272436. Intersection of A002113 and A034710. This sequence is obviously infinite. LINKS Chai Wah Wu, Table of n, a(n) for n = 1..10000 MATHEMATICA m[w_] := Flatten@Table[i, {i, 9}, {w[[i]]}]; palQ[n_] := n == FromDigits@ Reverse@ IntegerDigits@n; all[upd_] := Union@ Flatten@ Table[ FromDigits /@ Flatten[ Permutations /@ m /@ Select[ Flatten[Permutations /@ (IntegerPartitions[d + 9, {9}, Range[d+1]] -1), 1], Times @@ (Range[9]^#) == Total[# Range[9]] &], 1], {d, upd}]; Select[all@13, palQ] (* Giovanni Resta, May 06 2016 *) PROG (PARI) isok(n) = { my(d = digits(n)); (vecsum(d) == prod(k=1, #d, d[k])) && (subst(Polrev(d), x, 10) == n); } \\ Michel Marcus, May 07 2016 CROSSREFS Cf. A002113, A034710, A272436. Sequence in context: A305257 A318273 A061672 * A322516 A132080 A307636 Adjacent sequences:  A272811 A272812 A272813 * A272815 A272816 A272817 KEYWORD nonn,base AUTHOR Altug Alkan, May 06 2016 EXTENSIONS a(15)-a(29) from Giovanni Resta, May 06 2016 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 11 22:17 EDT 2021. Contains 342895 sequences. (Running on oeis4.)