A037050 Numbers n such that product of n with sum of next n consecutive integers is palindromic.

1, 121, 187, 14014

Offset

1,2

Comments

Also, number n such that n^2*(3*n+1)/2 is palindromic.

No additional terms below 10^10. - Jens Voß, Feb 20 2009

a(5) > 3.7*10^12, if it exists. - Giovanni Resta, Aug 26 2019

Links

Table of n, a(n) for n=1..4.

Example

187 * (188+189+...+373+374) = 187 * 52547 = palindrome 9826289.

Maple

A036659 := proc(n) n^2*(3*n+1)/2 ; end: isA002113 := proc(n) local b10, i ; b10 := convert(n, base, 10) ; for i from 1 to nops(b10)/2 do if op(i, b10) <> op(-i, b10) then RETURN(false) ; fi ; od ; RETURN(true) ; end: for n from 1 to 1000000 do c := A036659(n) : if isA002113(c) then print(n) ; fi ; od : # R. J. Mathar, Jun 26 2007

Crossrefs

Cf. A036659, A037051.

Sequence in context: A074730 A268519 A364778 * A275028 A036309 A346507

Adjacent sequences: A037047 A037048 A037049 * A037051 A037052 A037053

Keyword

nonn,base,hard,more

Author

Patrick De Geest, Jan 04 1999

Status

approved